It's been over 3 years since the last Paper Mario so IS has had enough time to make a new one. Plus the Paper Mario games are made on low budgets anyway so it's not like Nintendo is wasting valuable time and resources to keep the Wii U alive. Paper Mario isn't going to be a killer app that sells the NX and since the Wii U still has pretty good sized hardcore Mario fanbase, it's a nice way to keep the hardcore fans who own a Wii U still pleased while making a decent profit as well.
Seriously, the question isn't going to be if it's a remaster or a new game since it'll be a new game. The question is if it'll finally be a real RPG again or is Miyamoto going to mess things up again. Sticker Star was suppose to be an RPG like TTYD, but after Miyamoto was shown an early demo, he told the team it looked like a rehash and his advice was to remove everything that basically made it an RPG in the first place. When this man has no problem allowing the NSMB team to make 4 games that are incredably similar to each other but flips his **** when an RPG is similar to each other, that easily shows how much natural hatred he has toward this genre of gaming.
There's a reason Miyamoto has nothing to do with all of Nintendo's other RPG franchises. Hopefully the Paper Mario team doesn't invite him to look at their game this time since they should know by now anything RPG related he's not going to like.