Boon said we wouldn't have them sometime when the game was first announced

Exactly. He said that this time around, you'll actually have to beat your opponent completely up to win a round.

He said they won't be in this game, that they've done that idea and want to change things up a bit plus DC is involved, I doubt they'd want to see Batman fall into a meat grinder lol. I wouldn't be surprised though if they pop up again in the future.