As one of the people who wanted the Sound Four to be in, I'm kind of disappointed that CC2 did not implement these characters whom I felt really should be in the game for obvious reasons.
I just hope that they are added as DLC later on, than being completely forgotten and only support-only characters. The same goes for Anko and Kurenai who's fates are left as support-only characters as well.
Now there are about 4 more characters left to be confirmed I heard. Let's just hope these characters are worth it.