So there should have been people who, at the beginning of The Dark Knight Rises, could make the connection between Wayne's hermit-like lifestyle and the disappearance of Batman.
At the end of the movie, we see Wayne with Selina Kyle, and his "death" timed spectacularly well with the "death" of Batman.
Wouldn't people make the connections, and ultimately realize this? And since Gotham is a huge city, and Batman is probably known around the world, wouldn't people see a well and alive Bruce Wayne and be like, oh, Batman is still alive?