It'll be on NX...
That'll sell the console at launch guaranteed.
Most people don't want a Wii U.
Heck, I stopped buying software for my Wii U, using that cash for the NX.
Yeah i gave my Wii U to some kids my sister used to babysit because I didn't want it anymore, I'm certainly going to get an NX but the new Zelda would make it a lot sweeter to have one.