if there's a 7th (technically 6th) Smash game, I feel Waluigi is all but a lock - probably either the first or last base game reveal. ARMS is 99% off the table, given that it isn't that popular compared to Splatoon, got barely any post-release content and will be (even) old(er) news by the time Smash 7 even begins conceptualisation, a new Zelda rep of any kind (most likely not a new debut character through) also seems highly likely - through unfortunately I don't think it'll be Tingle, an indie game rep seems inevitable - especially Shovel Knight, a second Xenoblade rep could happen depending on how much the Xenoblade franchise grows in popularity, and I don't think there'll be a new retro, and if there is, it'll probably be Mach Rider, Excitebiker, a Hanafuda rep or Prince of Sable (as much as I want to believe Muddy Mole could get in, he clearly can't)
The Bulbasaurs in the movie were cute as hell.