They've been planning for this as a Wii U title for a long time. Wind Waker HD was an exercise to learn the Wii U to make this game. And it'd make this the first Nintendo console without at least one main series Zelda title. It's already the only console not to have a proper single player Mario game. The Wii U is a commercial flop, but it is by no means a bad system, and clearly an innovative system leading to some interesting ways to play; not a poorly executed prototye like the Virtual Boy. If we didn't release games if there was a new console coming out soon, then we'd just have huge launch lineups and dismal trickles inbetween.