Having Bale reprise his role as Batman would make this movie HUGE to maintain the continuity of the Nolan bat franchise and its success. However if they did that they'd be limiting themselves to the things that have been established in that Nolan universe such as the no super-powered villains, muted gadgets, lack of fighting skill Batman etc... That being said with Snyder's Batman you can expect a more comic booky Batman and different aethetic which doesn't mean the movie would be good though as we all know Snyder's reputation as a director.