With Bale, the series takes a step back into the darkness of Nolan's universe, rather into the future that DC would like to create to compete with the ever expanding Marvel Universe, which is headed for a second Avengers movie Age of Ultron, Guardians of the Galaxy, Thor: The Dark World, Captain America: The Winter Soldier, Ant-Man.
DC doesn't have their own film department, and are relying on Nolan to work magic after creating a sort of universe roadblock with his Batman trilogy.
Bringing back Bale shows a lack of faith in Cavill or anyone else to carry the character or the universe into a bigger, better and brighter future. The nod to Joseph Gordon-Levitt at the end of The Dark Knight Rises is rendered useless in addition to inane if he or someone else doesn't take over as Batman in the future.
And what of the way Nolan finished his trilogy?
John Blake/Robin is made out to be Bruce Wayne's successor as Batman, since Batman supposedly died in the blast, and Bruce Wayne is conveniently forgotten in the liquidation of his assets and left to gallivant with Selina Kyle in some cafe across the pond.
If Bruce Wayne returns, not only does it muddy the waters in a purported Superman/Batman team-up/crossover, but it neuters the impact Nolan was aiming for with his final opus.
Sadly, DC and all parties involved should start from scratch, or at least scrap the crossover.
If the ultimate goal is a Justice League movie to rival the Avengers movies, they need to establish their characters before they have them interacting directly.
Man of Steel had enough nods to LexCorp and a nod to Bruce Wayne to generate interest in the interactions of their worlds. They don't have to thrust the Dark Knight back into the mix so soon.
As many issues that I have with Nolan's "universe" I would welcome a well done crossover, or at least a clear path to a Justice League movie. The Man of Steel sequel/crossover will likely make a metric f*ckton of money, but that doesn't mean it is a worthwhile endeavor the way they're currently approaching it.
Prepare for a disappointing movie. If we're lucky, it will be so disappointing that DC will pull its head out of Nolan's *ss and put together a competent crew to tackle their vastly complex and delicately balanced universe.
Don't hold your breath though...