Stoopid tinfoil hat theory:
I find it interesting that Smash/SE may announce a DLC character so far in advance before they release (even before PP comes out). Mewtwo was the only character to do this previously, and he came out ~4-5 months after being announced.
Anyway, my stoopid theory is that Square Enix is actually getting 2 DLC characters. Yes....2 of the 5 slots. Square is the only 3rd party, save for Bamco, with 1 character. We know that multiple DLC characters have been available at once before. Mewtwo and Cloud were alone, but Lucas, Roy and Ryu were all released the same day in June, while Corrin and Bayonetta were released the following year in February.
I think the fact that Vergeben is hearing tons of names is not only because they are trying to throw off the scent of who the character is, but WHOM they are, because spitting out a bunch of names makes it that much harder to pinpoint both of them.
Now....back to my Mewtwo statement. He was announced 5ish months before release. This is where is gets especially dumb, but here we go: The SE characters get announced December 6th 2018, with a release for both together in March the following year (a month or so after Piranha Plant).
Guess which games came out around that time? That's right ladies and gents: Chrono Trigger and SMRPG, literally March 11th 1995 and March 9th 1996, respectively.
Square is going to do a double reveal of Chrono and Geno:] That way Sakurai gets what he wants and SE gets more classic exposure.
...or it's just going to be Sora or some other more modern SE character.
Just let me have my fun please.