I'd love to see them release red-green versions of the characters/items for Paladins & Dragons and the other expansions as well.
I can't remember where I saw it but I think that it was a comment from somebody at Asmodee. It was implied that they would release the expansions for the Red/Green versions at some point in the future.
They are in it to make money and if they sell enough 3/4 player expansions, I am sure they would consider releasing the other expansions for 3/4 players. They really have no extra developement costs involved, they just have to change the background color on the counters. This would also give them a chance to release more boards.