I don't think it was ever confirmed for March 2017. The NX was confirmed for March and Zelda U was delayed to 2017, so they probably tried to put it together.
There's basically no way it isn't planned for March 2017 to launch alongside the new system. Seems silly to make an announcement about a game at an event for shareholders when that game isn't even launching in the current fiscal year.
Whether they're ready to commit publicly to that is another story.
Twilight Princess was scheduled for a simultaneous launch for Wii and GCN until about a month before release. Yes, I'm banking on Nintendo to predictably change their plans
Twilight Princess was scheduled for a simultaneous launch for Wii and GCN until about a month before release. Yes, I'm banking on Nintendo to predictably change their plans
Yeah, I could see the Wii U version being held back until April, at least outside of Japan where Nintendo actually did release them simultaneously.
It'd be such a kick in the nuts to Nintendo's most dedicated fans who essentially got 3 years of support, instead of 5 with GC, that I think they might actually release them at the same time, however.