>>718115806
I don't think it's likely. Most Smash characters are added because they're
>promoting brand awareness of an existing, active Nintendo IP
Splatoon, Animal Crossing, Xenoblade Chronicles, ARMS
>a cross-promotion with an IP with a recent or upcoming game
Joker (P5 Switch release), Sephiroth (FF7R), Sora (KH3), Kazuya (Tekken 8, also as thanks to Bandai Namco for working on Smash)
>pure, autistic fanservice
K. Rool, Banjo, Terry (Sakurai is a big King of Fighters fan, although KoFXV was released only a year or two later)

Maybe Duskbloods will be beloved enough that it bleeds into the fanservice category, but I feel like it won't be relevant by the time Smash 6 releases, let alone is even announced. But who knows, I'd like to see it.