To be fair, Sonya deniers are reaching at this point. You can be skeptical, but to be outright convinced of her exclusion is pigheaded at best, given this laundry list of possible evidence:
-*NEW* Sonya's face in the faction page
-Boon questioning the fanbase's leaps in logic about Cassie replacing Sonya
-Boon claiming there will be characters with aged variations (we haven't seen any so far!)
-Boon claiming family members will be doing fatalities on each other
-Adam Urbano accidentally saying you can play as Johnny Cage in the Gamespot PAX demo
-German Gamepro leak that also leaked Kano mentioned Sonya and Johnny as playable (tenuous credibility)
-Both characters survived MK9. Who else is gonna fight on the side of Earthrealm in the Netherrealm War portion of the story mode besides maybe Kenshi and Fujin?
-NRS has said time and time again that this game is "the passing of the torch between the old generation and the new". If Johnny and/or Sonya are missing, it isn't a torch getting passed, so much as a torch getting put out and replaced.
-NRS loves including most, if not the entirety, of the MK1 cast in every next-gen MK game, because they are the dearest to them and they like to revamp them with whatever gimmick they're working with at the time (in this game's case: variations).