Hopes: Arle and SpongeBob (meaning that once Arle shows up, I'd take anything, not literally SpongeBob but he's a part of anything and my go-to for filler choices that won't actually happen). There is a second pass, after some time, and if she's not here, Arle is among them.
Hopes more people would consider realistic: I'll just settle for Crash. Lloyd would be awesome too. After a year or two, we do get a second pass.
Expect, if Costume Theory dies: Crash Bandicoot and one of the following: Doom Slayer, Lloyd Irving/Yuri Lowell/Heihachi, Frisk/Sans, or Leon/Jill/Monster Hunter. This is the end of Smash Ultimate DLC.
Expect, if Costume Theory proves true: Lloyd Irving/Yuri Lowell/Heihachi Mishima/Nightmare and Leon/Jill/Chris/Wesker or Monster Hunter/Phoenix Wright/Amaterasu. This is the end of Smash Ultimate DLC.
Frontrunners if a second pass is confirmed, more of the first (new companies focus): Any of the above from Non-CT who don't get in, with a few more like Hollow Knight, Ryu Hayabusa (who could even show up in Pass 1), and even more that I can't name. THIS is the end of Smash DLC.
Frontrunners if a second pass is confirmed, more of the first (bulk up repped comanies): Arle (I will acknowledge that Kazuma Kiryu has a chance so Sakurai doesn't smite me), Monster Hunter/RE/Phoenix Wright/Amaterasu, Lloyd/Yuri/Heihachi/Nightmare, Goemon (can't think of a way for Gradius to work, and without Bomberman...), Crono/Lara Croft/Gex.
Frontrunners if a second pass is confirmed, Spirit promotions: Bandana Waddle Dee, Shantae, Geno, Paper Mario... uh, those are the only four I can think of. Maybe Tails if they decide to go that route.
Frontrunners if a second pass is confirmed, Assist and Spirit promotions: Waluigi, Isaac, Shovel Knight, Bandana Waddle Dee, Shantae, maybe Bomberman.
I like to have my bases covered.