Oh boy, I come back to a lot of things- Especially the Blog/Music theory. Now that's a nice one!
I believe the Music theory is true, especially if we take the Blog Update delay in count. Which mean beside echoes (Like Ken if Vergeben is real) it doesn't leave a lot of series with possible newcomers. Very interesting. If Vergeben is right, it might lead to Incineroar and might Kill/Decrease the chance of some newcomers (Like Bandana Dee/Geno/Skull Kids)
Now then, if I may take a stance on the whole Square-Rep being DLC or not:
Let's be real. The game industry and Nintendo's vision changed ever since the last game. And I'm absolutely sure that there is a tiny team already thinking of the "after release" of Ultimate. Yes. Not everyone is 100% On polishing and such, maybe 98% but those 2% are probably still planning the future.
Now then, nothing say that the Square Enix Rep won't be in the base game of course, it might, and probably WILL happens, however, lemme put this scenario down for you.
-Sakurai make game document back in 2015
-Go back to get licence for veterant/Newcomers/Music and such.
-Sakurai asks to Square for that newcomers alongside renewing Cloud's Licence.
-Square are absolute ass and say no, accept for Cloud without new music
- INSERT TWO/THREE YEARS OF DEVELOPMENT
Now two possibilities are here first one:
-Square get back from their decision mid-way through the development, or very near the end.
-Accept to lend that characters only if they get a cut in sales
-Block Sakurai from Base game, but Sakurai really want to put that characters in so it becomes first DLC
-Team start working on that characters knowing it will be DLC alongside the polishing and stuff
-Both Nintendo and Square win more money because of DLC sales.
Second possibilities:
-Square backtrack and say yes for the characters BUT too late
-Sakurai really want that characters in, but he can't delay the game. Nintendo Excec say it must be NOW, no Delay. Big marketing campain for 2018.
-Oh well, Sakurai have to make it DLC
-Nintendo and Square are Happy, more moeny thanks to DLC sales.
This might sounds cruel, and disgusting, but as someone just doing some low-class scum job stage who roamed in two game studio and one being Ubisoft I can say, DLC are sometime though about, or planned ESPECIALLY during that polishing stage of the development.
BUT like I said, the fact that the Square REP might be base-game STILL EXIST and will probably happens, just want to bust the bubble of people thinking DLC aren't in planning stage, or aren't already being made by a small team.
Anyway, My takes on who it might be?
-Dragon Quest Protagonist ( the one witht the best chance tbh. I think it might be Eldrick or Eight. I wish for Eight tbh by pure Nostalgia google)
-Geno (The music theory hurt his chance a biiit. But there a chance that he might get his own Icons? Maybe not? However, I'm 100% sure the second Mario Icon in the music is Mario Kart...Not just for Spin-off, it has been the same since Brawl.)
-Sora (Yes, It's a Disney Characters, but since we had to wait until freaking March of this year to get the OFFICIAL confirmation about it removing all doubt, and the game still having tons of square Influence, it wouldn't be far-eached for someone to still put him in the Square Case, since well...The game are made by Square)
-Another FF rep? The music count being a fake out? (I don't believe this at all. I think Cloud is all we get.)