I'm not saying it's going to be EASY. But someone, at some point during the next-gen, is going to point out how much money is being left on the table by both Warners AND Capcom, by not combining the two for a single one-shot. And as such, the licensing deal will go through, and either Netherrealms or Capcom is going to go to work blending the two together.
It really isn't THAT hard. Money talks, and the complications in pushing this deal through are WAY less than Warners and Disney coming together to license a fighter featuring Superman fighting Spider-Man.
Again - you're comparing companies that aren't even remotely similar, or do business even remotely similarly. Warner Bros is not Tatsunoko is not Marvel is not SNK. The precedent you're claiming isn't actually precedent because the people in charge at Marvel aren't the people in charge at those other companies at those other times. There isn't a tried and true formula to shit like this. There's money, and the prospect of it made, or left on the table.