My theory for what happened to Officer Blake after The Dark Knight Rises
We all know that in the ending of TDKR, it is implied that Batman fakes his own death to redeem himself as the hero of Gotham after killing Harvey Dent in TDK.
Some people imply that Bruce Wayne gives up his life as Batman to live his life quietly with Selina Kyle, and that Officer Blake becomes the new Batman. But that makes absolutely no sense.
Officer Blake already reveals his birth name as Robin. Therefore, the logical tie here is that Officer Blake goes to the Bat cave so that Batman can secretly train him as Robin after faking his death. Adding onto that, I don’t think it makes sense that Bruce Wayne would give up his life as Batman after the reactor explosion. The only reason Bruce wanted to live a life beyond Batman was because of Rachel, who already died in TDK and chose Harvey Dent over him anyway. That was the only reason Bruce wanted to stop being Batman. But with Rachel not in the picture anymore, it kind of kills that argument. Also, I don’t think Selina Kyle would stop being Catwoman, so why would Bruce stop being Batman?
My guess is this:
Bruce Wayne/Batman fakes death. Batman secretly trains Officer Blake as Robin. Bruce and Selina keep a low profile abroad while maintaining their influence in Gotham.
Also, I think it can be safe to assume that Officer Blake becomes Nightwing after being trained as Robin. While his name isn’t Dick Grayson, and nor was he adopted by Batman (as per the comics), his origin story with his parents deaths loosely aligns with that of Dick Grayson.
At the end of the day, who knows. This is just my thoughts.