My full DLC prediction is this
1) Geno - SE is being very stingy with their ip's, yet they let them use Geno and Mallow for spirits. And since we know we're getting a SE rep, it makes sense for it to be Geno because they don't have to complicate negotiations or anything like that, and could release him alongside Piranha Plant, the other Mario character (also Geno's mii costume is missing, hmmm)
2) Monster Hunter - Did people already forget about this? It's music is listed with the other fighters music. But sure, that may not be enough evidence, but it's also Capcom's best selling series, has Rathalos as a boss and assist trophy, had mii fighter costumes in Smash 4 that didn't return for this game, a Monster Hunter movie coming soon, and the fact that of all the 3rd parties, Capcom has been playing the nicest with Nintendo (Ken, all the Street Fighter spirits and all the Mega Man and Street Fighter song remixes), so it would only be fair if Nintendo returned the favor by promoting their games that are often released on Nintendo consoles. Also Monster Hunter was in MvC:I...so there's that.....
3) Banjo-Kazooie - After the post I made earlier and all the evidence surrounding the fact that Rare is working with Nintendo on this game makes me strongly believe that Banjo is coming, and will have a lot of Microsoft and Rare content to boot (inlcuding an Ender Dragon boss perhaps?)
4) Sega Rep (Tails or the sleeper pick, Axel (Streets of Rage)) - ok here me out. If SE gets another 3rd party rep, then that leaves Sega and Namco as the only 3rd party companies to only have 1 rep. I'll talk about the Namco rep in a minute, but Tails and Axel are likely for their own reasons. Tails had a mii fighter costume in Smash 4 which is now gone and is a much better Sonic rep than Knuckles or Shadow change my mind. Axel is likely because he could be a nice Sega throwback character, and Streets of Rage 4 is coming out soon, so what better way to promote the game than by putting him in? Just an idea
5) Namco Rep (Heihachi, Lloyd Irving, Yoshimitsu, I have no clue) - This is the only one i'm kind of going to cop out on. While a Namco rep seems very likely, which one we're getting is beyond me. Heihachi was considered for Smash 4, Lloyd has somewhat of a history with Nintendo and in his home game literally controls like a Smash character, and Yoshimitsu, while not as popular, is a character that would fit into Smash nicely, have a fun moveset with him and could represent Tekken and Soul Caliber at the same time (cause he appears in both consistently)
Let me know what you guys think! (I didn't say Dixie because she has a mii fighter hat in the files so rip)