Oh, sorry, I didn't mean the game would be wrong, just to hear that someone like Freeze wasn't in a game about Batman seemed wrong. I always felt for the man and his situation with Nora and all, so I had a small soft spot for the dude.
As far as games go, the only things I can see being "wrong" is if there were voice-acting faults or program code glitches. Then again, script writing is more important. Give me a glitchy game with crappy acting and I can just mute it, wait out the lag, and enjoy a damn good story as I get "game over" after "game over" XD
I can see DLC being used to explain the origins of the character, which would make sense given the nature of the game itself (it takes place early in Batman's career).
I hope Freeze is well-integrated into the story rather than just throwing him in for the fans. Though as long as it doesn't mar the game quality or gameplay itself and they just add him in (which it sounds like they're doing more than that) I don't see any problems with it.