The two problems I have with this theory is that to me, it seems too clever, if you know what I mean. This is the kind of story you would see in a complex batman comic and not a movie. Also some people will quite enjoy the jason joker thing in the movie if the theory is true. But others won't like it because not everyone knows who jason todd is, and when they think of robin, they think of dick grayson. And then they will do some research and be like " oooooohhhhhhhh........... well I wish I knew this beforehand."