T minus 5 days until we know one way or the other about the bear and bird's fate. Though there is the third option that they're in the game but not confirmed at E3, but I don't think I could handle another few months of this so I hope E3 confirms it one way or the other.
As far as other characters I'd be hyped for, Banjo is obviously the big one. If they get in, I'm done with speculation and character-requesting, at least until the next Smash game. However, there's been plenty of characters that have been deconfirmed (counting spirits as deconfirmation) that I would have liked to see, such as Shadow, Geno, Dixie Kong, and Waluigi. But those are sacrifices I gladly made for getting K. Rool and will gladly make again if Banjo gets in.
And as far as characters whose fates are still in limbo, I am partial to the other characters from Google theory (Doom Slayer, Ryu Hayabusa, Artorias from Dark Souls). Them plus Joker and Banjo is like a perfect Fighters Pass in my eyes. But again, give me Banjo and you could make the other three characters Steve, Sans, and Bubsy for all I care.
We have three characters hailing from M-rated games: Snake, Bayonetta, and Joker.
Here's a question for you: what traits, besides the blood and gore, is Doomguy, and overall the Doom series, known for? We know Sakurai wants to make characters feel as if we're playing that character or the game they're from.
I only played the 2016 game, but he has a large arsenal of guns and could lean towards the more explosive ones like Snake. Then again, Joker has a literal gun so who knows how things work at this point. I think a main "mechanic" of his could be weakening his opponents from afar to a certain point, where they become vulnerable to a special melee finisher for a lot of damage. Which is Doom 2016's combat in a nutshell.