Here's my updated roster with Little Mac's confirmation:
I've also added Isaac as an alternate option to Robin just for the hell of it. I wanted to include Isaac in the roster from the beginning but I couldn't find the room for him and he was my least expected newcomer, so I just left him out before; now that I removed Chrom as an alternate choice to Robin, and since Robin and Isaac are both sword-wielding magic users, I figured I could lump them together.
The Wonderful 101's sales shouldn't matter at all. The roster would have been planned out before The Wonderful 101 was even released. And characters aren't just put into Smash Bros. for promotion, you know. Also, the fact that a The Wonderful 101 character wasn't revealed around the release of The Wonderful 101 doesn't mean it's not going to happen. You could say that the release of Pokémon X and Pokémon Y was the optimal time to reveal a new or returning Pokémon character (Pokémon Trainer, Lucario, Mewtwo, or Jigglypuff would have all been pretty relevant), yet we got nothing.