Honestly, even if this was real I wouldn't be that excited honestly...
But maybe I'm biased because I have the game readily available. Because honestly besides being on the 3DS, I couldn't see them changing much at all, and I'd rather see them take another stab with the basic Sticker Star formula (which had potential I still think, as I thought the basic battle system with a few meaningful tweaks and more plot utilizing the world map would be good), rather than what would probably be a quick and dirty port. TTYD seems like a hard game to edit? At the most, I'd love to see an optional section expanding on Ms. Mowz, and maybe fix some of the slower points in the Tree, Glitz Pit, and Steeple chapters...but I guess that might also mess up the game's pacing. It's really a hard game to reach a nice balance with a remake I feel.
I think Paper Mario 64 is more deserving of a nice, upgraded port, cleaning things up a bit, and if that was what was "leaked", I might believe it since it'd go with the weird Bombette shout-out by Nintendo.