Isabelle
Chance - 37.5% - A decent shot, but no where near guaranteed. She's a big name, for sure, but I'm not convinced that she screams "make me playable."
People have been claiming using projects as a teraforming set, but the question becomes a question of "why teraform?"
Villager's tree can be both an offensive tool ether when grown or chopped down. Even then, though, most prefer to use projectile play and direct fighting over trying to use tree set-ups. Typically, most villagers will end up using the tree only about twice in a single match, and only then rarely does it pay off.
So what benefit will Isabelle get when she makes whatever? Because right now I only see the buildings being a wall, which isn't good if they go crazy with it. Walls, as we know, are terrible to fight against competitive play, and if used exclusively as walls there is a very delicate balance to make it work. Too much health and the walls can promote too much keep away to the point that you don't interact much with the opponent, too weak and the setup probably won't be worth it. Even then, Smash favors mobility heavily. Most characters will end up simply rushing her down before she even has a chance to place a single brick, and those that aren't are typically heavyweights who will tear through buildings like a Kaiju. Factoring in a fun factor on how it feels to fight against, and I'm not certain teraformers have much place in Smash.
So if you take that away, what you have left is essentially scraps from Villager, and that's not exactly riving. Sure "clumzy acidents" are a cute aesthetic, but that doesn't translate well into forming a way to play.
Want - 30% - See above. I'm not certain if putting her in is a good idea for Smash. Her play style would end up being more keep-away than Duck Hunt, and they already get some flack for that.
Prediction
Micaiah - 3.42% - Less likely with every year.
Nominations
Masked Dedede Final Smash X5