Well, we now know the first will be an Arms fighter. I'm going to put my vote for Min Min. I think this pack will have more female characters and she is popular.
Platinum Games and Nintendo have a good relationship and a stylish rep they could add to be there alongside Bayonetta is Viewtiful Joe.
Pokémon Sword and Shield are huge so adding a Gen 8 Pokémon is a no brainer. I think it'll either be Rillaboom, as Smash has a final evolution fire and water starter but not grass, or Urshifu to promote the DLC.
Tekken is the biggest fighting franchise without a fighter in Smash and Heihachi is the obvious poster boy for the franchise.
This is the choice I'm most unsure about but Pauline could be added as another Mario representative and another female character to capitalize off the continued success of Odyssey.
Last, but not least, with Nintendo and Microsoft working together so closely, Master Chief is a great choice to break the Internet. It would be an amazing reveal to cap off the Smash DLC.
I've been trying to figure it out myself, but I think the biggest possibilities for the final three DLC slots are as follows:
9. Crash Bandicoot
Doomguy and Crash are really popular guesses right now, but Waluigi is someone I find extremely likely. I know, I know, but hear me out: 2021 is Waluigi's twentieth anniversary. But moreover, Ultimate might be Sakurai's final Smash game, and to end the Waluigi memes once and for all would be one epic sendoff.
I've heard people talk about Ryu Hayabusa, and while I would prefer him to Crash, I think Crash is more likely, more significant, and would make more people happy. Doomguy and Master Chief are interchangeable. Now that Bethesda's owned by Microsoft, they're both equally as likely. I hear talk about Rayman, and I don't think he's relevant enough to make it in. Arlo's 2021 prediction video mentioned Dr. Eggman, and I guess there's a chance, with 2021 being Sonic's 30th anniversary, et cetera. I really would like to see Eggman, but a new IP being represented is more likely. One of my top picks is Kamek, finally giving Yoshi's Island extra representation. Also, Samurai Goroh, but if anyone's going to be promoted from Assist Trophy to Fighter, it'll be Waluigi.
Y'know what? Imma predict Waluigi's reveal trailer. It'll be a fakeout for a new Mario Golf, something everyone's been predicting. Waluigi hits the ball and misses by a longshot. He runs over to get the ball, and from there it's the same as the game's first teaser. Everything goes dark, Waluigi looks up, and the sun is a Smash Ball.
The reveal will be near the end of 2021, (again, Year of Waluigi) and Waluigi will either be released later that same year for the holiday season or in 2022 for extra dev time. If Waluigi is released in 2021, the trailer will include extra footage of his moveset.
I've also been contemplating the possible return of Adventure Mode (the one from Melee, nothing crazy and cool like in Brawl). If it happens (which it likely won't), then it'll likely be DLC to give the devs extra pay for their troubles. I predict every series will get a level (possibly with a few exceptions, with games like Punch-Out and ARMS being impossible to be given a full level, in that case it'll just be a fight on a preexisting stage). It'll be either released alongside Fighter #10 (leading to further Waluigi rumors) or alongside Waluigi (for that epic sendoff).