The producer of Zelda: Breath of the Wild has admitted that having experimented with it, his team rejected the idea of incorporating Wii U GamePad functionality into the game.
We realized that having something on the GamePad and looking back and forth between the TV screen and the GamePad actually disrupts the gameplay, and the concentration that the game player may be experiencing,” Eiji Aonuma told Wired.
You have your car's GPS system on your dash. If you had it down in your lap, you're going to get into an accident!”
Off-screen play via the Pad is still supported.
Another interesting thing to note is that Anouma revealed that both the Wii U and NX versions of the game will play identically, thus confirming that a traditional stick-and-buttons style setup up is at the very least possible on NX, and possibly the main control system.
Added Anouma: I'm not going to create something where the users are going to have a different experience.”