If we're talking predictions, I've already posted mine elsewhere, but why not?
Admittedly, I feel like Monster Hunter's about as likely as Dante, and Impa could be another Nintendo character; I just figure that the rest of the Fighters Pass won't be entirely third party. (with Impa, it helps that next year's Zelda's 35th anniversary, she's pretty much the only major Zelda character outside of the Triforce Trio who isn't an assist trophy, and Age of Calamity seems to be making her fairly prominent)
Geno: I'm guessing that Steve and CP8 were intended for an E3 reveal before the schedule was messed up, and Geno fits the pattern of E3 ending on long-awaited fan favourites. (Ridley, Banjo) I could potentially see a reveal early on in November if the Nintendo online open tournament is any indication (seeing as Min Min was announced the day after the first one of those tournaments), and he'd be released before the Mario tournament, whenever that's going to be. (I don't know if we've gotten anything specific beyond "November or December")
As for why he's likely, twenty-plus years of consistent fan demand seems to help. Square-Enix has been cooperating more than they were with Smash 4, their flagship franchises are already in the game (meaning that there's no clear front-runner), the unusually absent Mii costume (mind you, Mii costumes from Smash 4 can still be revealed at this point, but you'd think that they'd have revealed it with Hero) and there's no way that anyone involved is unaware of the character's popularity among Smash fans. (on top of the Mario tournament's unusually vague release window, coupled with the Smash online open creating the possibility of an early November reveal, along with this year being the 35th anniversary of Super Mario Bros. - those could all be coincidences, though)
Dante: I feel like this could go either way between Dante or Monster Hunter (Phoenix Wright also seems like a possibility), but between
a comment by Hideaki Itsuno (which was followed by a DMC1 Switch port being announced about two months later),
Kamiya putting out a Twitter poll about who people wanted to see in Smash and then deleting it (he had to know what he was getting into with that, given his previous reactions to demanding Smash fans), and
a later comment that implied that he already has a second character in Smash, I feel like his chances are decent. Devil May Cry seems to be on the rise as of late - maybe not as much as Monster Hunter (which has a movie coming out and got a popularity explosion from Monster Hunter World), but enough that Dante seems like a strong possibility.
Ryu Hayabusa: Koei-Tecmo seems like the last big Japanese third party developer that doesn't have a playable character in Smash. Ninja Gaiden's got a history stretching back to the NES days and two very different types of gameplay between the classic and modern games (much like with Castlevania, it seems like there's a lot that the developers could do with that), and Koei-Tecmo's close enough to Nintendo that they worked on a main Fire Emblem game and a spin-off that's the canonical backstory for Zelda: Breath of the Wild. I'd be surprised if Ryu Hayabusa didn't make it in, to be honest. (and I have basically no experience with the series - I've only beaten my first Ninja Gaiden game very recently)
Impa: by the time that this Fighters Pass is done, it will be twenty years since a new unique playable Zelda character was added to Smash.
Twenty years. Between that and next year being Zelda's thirty-fifth anniversary, a new Zelda character seems long overdue. I don't know if they'd go with Impa based on Ocarina of Time, Skyward Sword, Hyrule Warriors, or Hyrule Warriors: Age of Calamity, but if we rule out assist trophies, she seems pretty likely if we do get a new Zelda character. As an alternative, I could see us getting Bandanna Waddle Dee, Dixie Kong, a Xenoblade character (Rex? Elma? Fiora?), a new Pokemon, or a Fire Emblem character from a game that hasn't been announced yet, but I figure that we're going to get another Nintendo character.
I'm not sure about the specific order, though I'm guessing (hoping?) that Geno is CP8, and after Bayonetta, I figure the developers are well aware that characters from action games will need a lot of time to balance properly, so I'd guess that Impa (or whoever the Nintendo character winds up being, if we get another one) will be at the end.
Honourable mentions go to a Namco-Bandai character (they seem oddly hesitant to include their own characters for whatever reason; you'd think that we'd have a Tekken character by now, bare minimum), Crash Bandicoot, and Rayman. (I don't think the entire Fighters Pass beyond Min Min is going to be third party)