Ok. Fighter pass 2 finishes. Sakurai releases 4 a la carte characters to fill out those slots in the code. Then, to really set the record and get the roster to 100 characters, he adds 8 echo fighters of base game characters. Who do you want to get added thusly.
So four unique characters and eight echo fighters? I feel like it depends on who we get for the rest of Fighters Pass 2, but let's assume that the alleged "leak" that's going around is true (unlikely, since it's an anonymous 4chan text post, but I'll go with it for simplicity's sake), and we get Rayman, Ryu Hayabusa, and Doomguy. If assist trophies and DLC Mii costumes are ruled out, my wants would be...
- Dante (Devil May Cry)
- Impa (The Legend of Zelda/Hyrule Warriors: Age of Calamity)
- Crash Bandicoot (Crash Bandicoot)
- KOS-MOS (Xenosaga) - I could have gone with a Tekken character, but I'm not sure whether Jin or Kazuya would take priority, and from what little I know about the three of them, KOS-MOS seems like she'd have the more interesting moveset.
As for the echo fighters...
- Octoling (echo of Inkling)
- Jeanne (echo of Bayonetta)
- Metal Sonic (echo of Sonic)
- Ms. Pac-Man (echo of Pac-Man)
- Akuma (echo of Ryu, though lighter and with his differences from the Street Fighter games)
- Liquid Snake (echo of Snake)
- Funky Kong (echo of Donkey Kong)
- James McCloud (echo of Fox)
Admittedly, the last three were likely a bit of a stretch - I was running low on ideas, since the only echo fighters that I really wanted were the first two and Tails (though he'd be stretching the definition), who has a DLC Mii costume.
(if it doesn't have to be echo fighters of base game characters, I'd replace James McCloud with Coco Bandicoot)
So yes, if it were up to me, we'd have Super Smash Bros. Ultimate with New Funky Mode and featuring Dante from the Devil May Cry series, though I'd want those characters (& Knuckles) for more than just the memes. (If there was more room and I wasn't as strict about what rules I use, I'd include Tails, Knuckles, and Dixie as well, at the very least)