I think you're really misinterpreting Sony's role in this. And this is a HD remaster. How many of those have you seen when they have started to cut and redefine the gameplay?
Agreed. Take a look at Sony's publishing history - does anyone honestly think they expected all, or even most of them, to do AAA numbers? I seriously doubt anyone thought games like Rain, Unfinished Swan, Echochrome, Flow or Vib freaking Ribbon were going to break any sales records.
Sony have a long history of supporting more niche titles, they know the value of being seen to encourage beautiful, artistic games on their platform. Rescuing a smart, beautiful, artistic game that has a 94 metacritic (with user score to match), regularly appears in all time best lists, and is on the Museum of Modern Art's acquisition list, yet had pretty much been lost to the ravages of time? Not only that, but putting it back into the hands of its original creator? That is one hell of a prestige point. I honestly doubt they're all that concerned about sales in the grand scheme of things; the marketing opportunities are worth more than it could ever sell.
And forcing major gameplay changes onto it would kill that good will stone dead. Not going to happen.
As to Double Fine throwing their weight around with regards to platform choice, remember that they're a small game developer in negotiations with not one, but two multinational media giants. Much as I expect that everyone is there in good faith, I would still want to pick my battles very carefully if I were in that situation.
Obviously I have zero clue what's going to happen, but if I were to hazard a guess I'd say PS4/Vita first, PC 1-6 months later (Win/Mac/Linux because Double Fine are awesome). Maybe a port to mobile after that (because Disney), though OTOH that might be seen as competing with Vita. Also outside chance it turns up on the PS+ freebie list the month it comes out on PC .
Disney is the publisher.