SlicedBread3
Member
To me, the fact that it's a free update and not paid bonus DLC, whether exclusive or not, suggests he was supposed to be at some point. Unfortunately we'll never know when this deal was actually struck. You can almost guarantee it wasn't recent, though.
They announced ages ago that all DLC characters will be free. This is the third one announced. (Ant-Man and Hawkeye being the other 2).
To be honest I don't think this will end up being much different to when they had Joker as an exclusive playable character in the Arkham games.