On Friday morning, Motorsport.com revealed that Allison is going back to the previous position he held at the team, with his successor Mike Elliott swapping roles in the other direction and becoming the team's chief technical officer.
In several ways, this is starkly new ground for the modern Mercedes squad, in that it finds itself in such dire straits compared to its years as F1's dominator that a major change to its technical staff has been felt necessary and that it hasn't been able to close a gap to a competitor with an initial car design update plan, as it did successfully, for example, in 2021.
And just two weeks ago team boss Toto Wolff was publicly stating that Allison had not returned to directly working on the Mercedes F1 car project from his part-time role as CTO. This also involved working with the America's Cup team established by Mercedes co-owner INEOS.
At the same time, the reshuffle is very Mercedes.
Wolff says it was at Elliott's urging that the change was made. That Elliott felt "with James we have a gladiator on the field and the troops are going to go through the fire for him and with him". There has so far been no official press release message from Mercedes that the change has been made and that is understood to be remaining as the case, which softens the impact for both Elliott and its organisation overall. But the team wanted the news out there in its own way, giving Motorsport.com F1 editor Jonathan Noble an exclusive interview with Wolff to discuss the development.
This is both an attempt at preserving its much-vaunted united team culture and also, apparently, a bid to stoke its fire and revitalise its fortunes in F1 competition.
What cannot be fully known right now is how much Elliott's decision was reached in reaction to the internal pressure at Mercedes that had been building – to recover from being so significantly knocked off its perch at the head of the F1 field by the 2022 rules reset and the return to running ground-effect cars.
It was always possible that one of the leading teams come 2021's end and the new machines finally being introduced would lose their place. But while Mercedes fell so dramatically with the badly porpoising W13, Red Bull maintained its place at the sharp end and then roared clear once the RB18 and its downwash approach were lightened.
That aerodynamic concept, at full play with the critical suspension and underfloor part designs Red Bull has also nailed, has proved to be the best of the new era. And the team that moved first and so decisively to switch to that path, Aston Martin, has leapt up the order as a result.
By implementing evolutions of their very different 'zeropod' and inwash-sidepoded cars at the start of 2023, Mercedes and Ferrari risked falling into their current positions.
That heaps pressure on top of frustration and actually eventually doubles – in that a wholesale concept change as Mercedes publicly committed to in Bahrain, but had been mulling for a while beforehand, now has to be pulled off successfully.
By apparently deciding not to commit to a concept change before 2024, Ferrari has tripled that burden…
Perhaps the most significant word of Mercedes' carefully curated change with Allison and Elliott is in Wolff's declaration that the change was "very much driven by Mike Elliott owning the process". 'Owning' suggests Elliott reacted to the shortcomings of Mercedes' technical team under his leadership, but the subsequent reaction from Wolff is again very Mercedes.
The axe has not swung for Elliott in the traditional F1 sense as it has for Mattia Binotto at Ferrari and James Key at McLaren. Instead, Wolff has kept Elliott onboard, and his position as a full-time CTO reflects the worth he clearly has to the organisation still on its books. Elliott will now address how best to deploy Mercedes' technical resources from an overarching organisation development perspective, with Allison directly working on how to make the W14 and W15 into winning packages.
There is also a secondary revelation from Wolff's words, which sheds light on how F1's other massive rules shake-up – on financial matters – has impacted Mercedes' previously uber-successful design team.
This is that chief designer John Owen "became a cost cap administrator", per Wolff, with "a tonne of extra work that comes with it" post-2021. Now, Owen returns to being more focused on car design, with his deputy Giacomo Tortora moved into an engineering director role and helps with cost cap resource division work. This harks back to the time Aldo Costa worked alongside Owen and Allison in that job before he left to run the technical department at Dallara in 2020.
Because major change has happened within Mercedes's technical department through its time heading F1 between 2014 and 2021 – with other engineers being moved into more senior management roles, and perhaps most famously, Allison's predecessor, Paddy Lowe, leaving to join Williams as its technical boss in 2017. Yet then, the then Silver Arrows squad carried on winning.
Things are very different for Allison and Wolff now. It's no coincidence that Aston is doing so well having hired ex-Red Bull aero chief Dan Fallows, but also former Mercedes aero leader up to late 2021, Eric Blandin, as deputy technical director. So, rather than the top of the pyramid being replaced, the critical inner structure is, metaphorically at least, weaker than it was when Allison handed over Mercedes' technical director reins in early 2021.
That, therefore, focuses the spotlight on this new development. Mercedes is shifting the responsibility that comes with the pressure to return to winning ways to Allison, but it has done this precisely because of his value to the team.
It's worth remembering that Allison expected to be "stepping away to my sofa to cheer the team from the sidelines as a punter," when he stood down as technical director, wanting to avoid "becoming an old embarrassment".
But instead, Wolff created the part-time CTO role for him and kept it in-fold, a decision which appears to be paying off significantly right now in that Mercedes has a proven technical director to try and revitalise its fortunes. At the same time, the major role swap reflects that a key moment in Wolff's Mercedes leadership – its second technical director change – was ultimately unsuccessful.
But Wolff's explanation of Allison's "gladiator" worth via Elliott reflects that Mercedes thinks this third technical director appointment will be a well-received reshuffle internally.
Allison is a popular and respected figure amongst Mercedes' staff, while his amiable and detailed persona chimes with its fans too. Allison bringing that back to F1 also restores what Mercedes had lost on this front by losing the very polished and comprehensive James Vowles to Williams.
Allison also possesses quite the F1 track record. He worked as aero chief at Benetton during the Michael Schumacher/Ross Brawn years, then followed that superteam to Ferrari and was an important part of its whole most-recent period of F1 domination up to 2005.
In that year, he joined Renault as deputy technical director and won two more title doubles with Fernando Alonso.
The Spaniard was therefore delighted when Allison rejoined Ferrari in 2013 – first as chassis technical director and then overall technical director – having had his stock and profile rise by the then Lotus machines designed under his direction winning with Kimi Raikkonen and bother Sebastian Vettel's Red Bull with Romain Grosjean.
That second Ferrari stint didn't work out, with Allison much less hands-on design-wise on those red cars and then also sadly having to deal with the death of his wife in 2016, shortly before he left the Scuderia to support his family.
F1 was then somewhat surprised when initial expectations he might eventually rejoin what was back to being called Renault again turned into his arriving at Mercedes for his first stint as technical director in 2017.
His work on improving Mercedes' chassis designs, always considered weaker overall in the early years of the turbo hybrid era compared to Red Bull, but boosted superbly by the team's engine output, became ever more critical as the power unit stakes stabilised. Ferrari (controversially) and Honda (surprisingly) eventually overhauled Mercedes on this front, but it kept on winning in the ultra-high downforce era.
Allison didn't lead the technical department that produced the W08 during its initial design at the start of that era, but by the time that rules period ended in spirit in 2020, his team had made the W11 with its DAS innovation, a package that restored Mercedes' advantage to the huge margins of 2014-2016.
That car will surely go down as an F1 legend, but to be produced in an era of rules stability was seriously impressive, although of course also boosted by Ferrari's disappearance from contention thanks to its engine design "settlement" with the FIA at 2020's start.
But just because Mercedes has returned to the technical department leadership that brought it to previously unscaled F1 success heights and the last titles of its record eight successive in the constructors' championship doesn't mean it will instantly be winning again.
Indeed, Allison must galvanise that now altered technical structure and then lead it to take on Red Bull's current crushingly superior position, treading a concept path Mercedes' rival fully laid down.
But convergence is always likely in any new F1 design rules era. What was unexpected was Mercedes' team culture and the decisions surrounding Allison's succession as technical director being so tested in the squad having produced two poor cars in a row. Therefore, such a reaction as has been seen today couldn't be foreseen until it had to be considered.
But the upcoming results of that unexpected challenge for Mercedes and Wolff will be the story of how a modern F1 superteam fully evolves. Mercedes has either peaked and cannot climb so high again despite its moves to correct its slide. Or, its current poor predicament is but a brief dip in between winning chapters.