I think Sephiroth showed just how impossible it is to predict what's coming next. No one thought it possible, yet here we are. I was so sure Rex would be one of the final 3, but now I really don't think it's happening. So now I think my prediction for the final 3 is gonna go something like this:
9. The Knight / Hornet (Hollow Knight)
10. Doom Slayer (Doom)
11. Crash Bandicoot (Possibly with Coco)
Here's my reasoning:
Hollow Knight is an indie game, yes, however it is a fairly popular indie game with a new title being introduced in the series sometime soon. We've had more popular indie reps like Sans and Cuphead entered into the series as Mii costumes which seemed like it was going to be a trend, but it quickly subsided when there was no other deluxe indie Mii costume for the next 3 patches. I feel like if any indie rep is going to take a spot at this point, it'll be The Knight or Hornet.
Doom Slayer I think is a long time coming. Doom is pretty much the father of first person shooters, a genre not really represented in Super Smash Bros. If there were going to be a face for the genre (One who helped define FPS games), it would be the Doom Slayer, James Bond, or Master Chief. One absolutely cannot happen (James Bond), Master Chief is a Microsoft character that's never appeared on a Nintendo console, leaving Doom Slayer.
Crash, again, is a long time coming. Mario had two rivals in the early 90s; one for his 2D games (Sonic) and one for his 3D games (Crash). Crash, like Mario and Sonic, had worldwide popularity and was the unofficial mascot of Playstation in the early days and now just drifts to all consoles much like Sonic does. Of course one of the biggest cases for Crash is that he had sizeable popularity even in Japan despite being a western made character, much more than you can say for his later counterpart Spyro (Who was completely ruined in Japan). It's a good opportunity to add in Coco as well since she plays identically to Crash in the most recent games (Only difference being she uses a butt stomp rather than a belly flop)