And a brand new Mario or Zelda would do that alongside an enhanced port of Splatoon and whatever else they may have. They don't need both at launch. One of the things that Nintendo has struggled with as far as their consoles go is keeping up the momentum after launch. So, they could launch Zelda alongside the console and then have Mario a month or 2-3 months down the line. That would keep the ball rolling. That could lead into that enhanced port of MK8, which is said to be extensive. Emily has claimed that Retro's game would be released next year, so that could be positioned as their big, or at least one of their big holidays titles.
The most important thing for them to do is to at least keep a steady flow of first party releases. They don't need to go all out for launch day. One game that people feel they need to have is really all you need. All you're trying to do there is get the ball rolling.