Yoshi K
Come with me if you want cookies
Now, I'll try to formally format the unconfirmed vets into whether I think they'll be back or not.
Ness/Jigglypuff - Members of the original 12, they're definitely going to make it.
Mr. Game and Watch/R.O.B - These guys represent Nintendo from the older days, I think they're in just for the sake of keeping classics.
Ganondorf/Meta Knight/Wario - They're relevant characters from popular Nintendo franchises. No reason not to keep 'em.
Falco - ehhhhh Star Fox hasn't been so popular lately but I still think Falco's good enough to make it in.
Wolf/Mewtwo/Ice Climbers - I feel these guys are toss-ups at this point.
Lucas - I don't think Earthbound/Mother is relevant enough to have two reps, basically the same situation as F-Zero
Dr. Mario/Young Link - Dead alternate versions can stay dead without trouble (besides Toon Link is already pushing it)
Pichu/Roy - Their series have too many reps
Ivysaur/Squirtle - There is no way more than one of the Trainer's Pokémon is coming back
Snake - We already have enough third-party characters
Mr. Game and Watch/R.O.B - These guys represent Nintendo from the older days, I think they're in just for the sake of keeping classics.
Ganondorf/Meta Knight/Wario - They're relevant characters from popular Nintendo franchises. No reason not to keep 'em.
Falco - ehhhhh Star Fox hasn't been so popular lately but I still think Falco's good enough to make it in.
Wolf/Mewtwo/Ice Climbers - I feel these guys are toss-ups at this point.
Lucas - I don't think Earthbound/Mother is relevant enough to have two reps, basically the same situation as F-Zero
Dr. Mario/Young Link - Dead alternate versions can stay dead without trouble (besides Toon Link is already pushing it)
Pichu/Roy - Their series have too many reps
Ivysaur/Squirtle - There is no way more than one of the Trainer's Pokémon is coming back
Snake - We already have enough third-party characters