I would prefer it on NX as a launch title.
The Wii U is selling bad and Nintendo can't keep releasing high budget games for it: Software has a hard time recouping dev costs already, how are they supposed to make money with a high budget, open world Zelda game that only sells 1-2m units on the on-life-support Wii U in late 2016? I'm sure Nintendo wants you guys to have your Wii U Zelda game but they can't continue to burn money on the console. The Wii U is a failed concept with an expensive controller their first party developers are still struggling to integrate into their games 3 years after the release of the console. They need to move on and release a new console.
Why on earth would Zelda sell that low. Even on crappy system sales of Wii U. Smash sold excellent. So did MK8. Zelda on Wii U would sell its normal 4 million easily. Even Skyward Sword being bashed to hell. And Wii dead. It sold that much. Unless somehow Zelda U has some huge change that is universally panned. Like hire the voices from the Zelda CDI games. Or pull a Metroid OM.