Batman: Arkham Knight will wrap up Rocksteady's trio of games starring the Caped Crusader, as the studio has made it clear they are moving on to new pursuits after its release.
With regard to why the team is stepping away from the franchise after Arkham Knight, Rocksteady's Dax Ginn told IGN, "We’ve done all we can do here. It’s…it’s kind of time for us to walk away from it."
Ginn then went on to add:
Anything we do is a collective decision between Rocksteady, Warner Brothers, and DC Comics. But it was something that we were really pushing for because we had a really clear vision for how this story should end, and the way we wanted it to end.
For us I think the Batmobile is that final thing. It’s such a critical part of the game, the epicenter of the design, but once we’ve done this, I don’t know we’re ever going to feel like we’ve missed out on a critical piece of what it feels like to be the Batman. That was kind of our driving force all along.