I think it's pretty likely it'll turn out he was brainwashed or something, like he's just.. brought back to reality post Death Metal/Doomsday Clock. He's a bit staggered and confused as to what the **** happened and he gets abducted by the League of Assassins who work their mojo until he inevitably breaks out of it and he and Damian team up and take down the bad guys at the end of the arc. I mean given that he seems to be wearing his pretty much his old costume it looks like his history is basically intact again.