We’re probably not getting an Indie character... but people like to dream, so let’s discuss the possibilities:
1) Shovel Knight - Very well known, very popular game, very easy moveset due to his diversity of moves. But he’s an assist, so it’s not happening. Maybe next time, partner.
1a) Plague Knight, Specter Knight and King Knight - while they all have their own campaigns, and specter knight would be one of the best characters ever, it’s not going to happen. Even with shovel knight out of the way.
2) Shantae - Is she really am indie? I guess? I mean WayForward just doesn’t seem like an indie studio. But she’s got plenty of games, plenty of movesets, and she’s been with ninty since the game boy color.
3) Commander Video - Not the most moveset potential in the world, but being from an endless runner would present a completely unique style unseen in the game before (never.. stop... moving... which for dashdancers, is fine.). Also he was a trophy in Smash 4, has become a Nintendo (timed) exclusive, while I don’t see us getting any indie character, I still see some content from this guy, even if it’s just the return of his trophy.
4) Juan - Wow that’s an easy moveset to put into a platform brawler.... and Brawlout already did... plus, Guacamelee is currently a timed exclusive for Sony. And well, no shortage of metroidvania characters on this list.
5) Isaac (Binding of, not golden sun) - A twin stick roguelike game is a genre that also has not been previously in Smash. Plus came as a switch launch title.... but this character is creepy, and his genre is mostly big outside of Japan... and not that big anyway.
6) Reimu - Apparently this person is big in japan. I’ve never even heard of their game.
7) Rusty/Dorothy echo - The steamworld Franchise is beloved, entirely on Switch, and presents a unique take on the Metroidvania genre in the two “Dig” titles. I’d love to see them, but I don’t think we’ll even see any content from Image and Form let alone their excellent character designs.
8) Worm (Worms series) - Not really sure if they’re an Indie, but Team17’s flagship series never really gets mentioned, despite being in a genre never before on the roster, having one of the easiest movesets to incorporate while still being unique, and a classic design. Imagine they are virtually unknown in Japan.
9) Travis Touchdown - Another one that like the Worm and Shantae certainly push the definition of what an indie is. He’s got a shot, honestly.