Yeah, agree that they can't all be guaranteed starters, veterans included. It did surprise me when he was revealed this time around, since it's been traditional for him to be unlockable. I know it was the year of Luigi and all, but maybe they just revealed him because it was a no-brainer that he'd be in it.
It does make me wonder how many surprises they are going to keep back, though, and how large the roster is going to be. (can't remember if a figure was put on it in the direct?)