With the Arkham franchise now in the rear view mirror fans of the Caped Crusadar are now wondering what Rocksteady has been cooking up behind the scenes, and it appears it will be yet again a new Batman experience, but this time done in Unreal Engine 5.

The new adaptation, which hasn't been officially announced by Rocksteady or Warner Bros., was discovered through a job listing for a Senior Core Engine Programmer on the Warner Bros website. The job listing states the position is located at Rocksteady Studios in London, and that the individual would have to have a high level of technical ability, be competent in C++, and have experience with Unreal Engine 5.
Notably, all of the Arkham games were built on different versions of Unreal Engine, specifically Unreal Engine 3, with titles such as Arkham City, Origins, and Knight heavily modifying the engine to push it to its limits.
It appears the next Batman game will be skipping Unreal Engine 4 and moving to UE5, which I don't believe many people will be upset about, especially considering the graphical possibilities with Epic Games' latest engine. The job listing also states that the position will include guiding the studio's content creators and game coders in optimizing the unannounced project for the target hardware, which is high-end PCs, PS5, Xbox Series X/S, and the "next generation of consoles."
I suppose this unofficially confirms the next Batman game from Rocksteady will be launching on the next generation of consoles. To check out the job listing for yourself, visit this link here.
Lastly, the existence of an unannounced Batman game falls in line with recent comments from Warner Bros. which announced it was concentrating on already established IP such as Batman, Game of Thrones, Harry Potter, and Mortal Kombat when it closed Middle-Earth Shadow of Mordor/War studio Monolith Productions.