So personal thoughts, taking Reggies 'new to smash' to heart:
Probable
1. FE: 3 Houses Rep
Nintendo called the shots for DLC and it just makes sense that they use Smash as a vessel for sales. I just pray its not a swordy. Plus I doubt Nintendo cares about the 'too many FE reps' discourse. With the release date coming soon, I'd expect reveal to be when PP is released.
2. Banjo-Kazooie
Nintendo knows they're highly requested, they fit right in, and Microsoft has been playing pretty nicely with Nintendo lately, plus the tweet. Makes a lot of sense, more-so if Rare plans on bringing back the series anytime soon.
3. Sylux
Conspicuously absent from spirits despite being relevant in the most recent games, and I've heard he is set up to be an antagonist in Prime 4. Again, his inclusion would be great marketing for the game if that is the case. If he was a trophy in prior smash games (honestly dont know) maybe that changes things, via Reggie, or the comments dont account for those, IDK. Just feels like not including him AT ALL is very weird. I imagine his reveal would coincide with a Prime 4 release date announcement. That game seems to be taking longer than expected, thus the 4th of 5 DLC.
4. Gen 8 Pokemon
By the time the final DLC rolls around Gen 8 should be released, and it only makes sense that one be included in smash. It only makes sense.
I Won't Be Shocked
1. Erdrick
He has legacy and SE needs another rep, and it sadly wont be Geno. Just hate that he's another swordy.
2. KOS-MOS
She's in Xenoblade 2 and has some legacy, and is very popular in some circles online. Plus it would be another Bamco rep.
3. Adol from Y's
NIS is getting along with Nintendo, and he has a ton of legacy, even if his series has never been super popular.
Out Of Left Field
1: Hallow Knight
Aesthetic fits smash, could do some cool things, reasonably popular
2: Randi (Secret Of Mana)
Again, SE needs another rep, and the Mana series has been dormant for awhile. Would love to see a moveset that incorporated most of the weapons, instead of being sword focused
3: Laharl
Again, NIS is a company that isnt represented yet, and Laharl is more or less their icon. Could do a lot with the moveset too.
4. Sephiroth
If you're gonna go in on SE might as well go all in on FF7 right? Considering villains were fairly prominent in ultimate he would help round things out. Plus meteor final smash would be sick.