Interesting to note that the game was running on UE4 as late as the 2021 showcase trailer.
Yeah, despite UE5 seeming to be ready-to-use tech in the May 2020 reveal (and thus assumptions that there were surely developers already using it behind closed doors, as was often the case in the past with engine technology by the time it was debuted to the public... I actually made this assumption in a post about GCD 2021 before The Coalition's Alpha Point showed to be a rudimentary experiment with the tech rather than a full-fledged showcase,) this tech was still far from mature and available for productions.
We learned in that Alpha Point post-mort that Epic did not give private access for UE5 even to developers as close as The Coalition (a team which is Microsoft's most important UE developer, responsible for evaluation and optimization of UE technology on Xbox in addition to making games; Coalition was also involved in Matrix Awakens) until November 2020. Coalition was still modeling Alpha Point in UE4 and other development tools through that Oct under guidelines and assumptions of the technology and concepts, to be ready for UE5 when they got access.
For most game developers, that Early Access release of UE5 in May 2021 was when they first got to try out the tech. Pros and the public got it on the same day, which is one of the reasons why there are so many amateur/indie "demos" using UE5 while there are still so few games and relatively few revolutionary showcases of the technology even 3 years after access.