The Wii U will be alive and well in 2016. Nintendo has already settled in for the long haul on it, otherwise games like Splatoon and Yoshi would not be coming out on the system.
Holiday 2017 is the earliest I would expect a home console to come out from Nintendo. Zelda will long be finished by then and out a year before that MINIMUM.
Also if you watch the delay video it is referenced to as "Zelda for WII U" multiple times /facepalm to anyone thinking the development is moving to another platform. If they where even considering it, they would have changed that really damn quick to "The next Legend of Zelda".