Honestly with so many variations and characters, nobody is going to main "everyone" at that same high level lol just too much shit to memorize, though I'm sure some will try out everyone but I think realistically majority will probably main 1, 2 maybe 3 characters at most for serious competitive play.
I have to see the full roster, I know we have like 50%+ revealed but still. I have to see if Fujin will be in, at this point he's the only one left I really care a lot about.
Definite mains:
-But if Fujin's in definitely maining him to the max.
-However, for the ones revealed. I will be trying out every possible, potentially good zoner.
-I plan on maining Ermac, MOS, Mystic. Probably not Spectral.
-Also IF Sektor or a cyborg that plays similar to him comes back or joins I will main them.
-Scorpion, Ninjitsu and Hellfire. I forgot about Inferno have to see more to judge.
-Raiden, Displacer only.
-Takeda(he seems to be one of the lesser popular characters so far) and he has whips or rope like moves which I like plus his backstory is really cool. Plus he seems like a cool new ninja character.
Possibilities, depends have to play around with:
-Erron Black, we haven't seen anything from him yet but if he has good zoning tools with the guns I may add him to my secondaries.
-Reptile, I was never a big Reptile player at all. In fact the only MK game I played him really was MK 4 of all games and a little in MK 2. Since then haven't touched him. He looks like he'll have interesting zoning tools with stopping that forceball set ups, they have potential. His Noxious looks tempting, practically free up close damage. Maybe his Deceptive I'll try out, not so interested in his nimble variation.
-Kitana's Mournful variation, a lot say it looks crappy and of her 3 that may be true but I think she has good zoning potential with this style so I'll experiment. Probably very small chance of me using her right now though but it looked kind of interesting.