Here's how I see the NX launch playing out in an ideal world.
Nintendo typically makes 20 games a year. Thanks to the combined development platform we know the NX will likely get all 20 games. Plus a few WiiU ports
Launch - Zelda BotW, New IP, Racing Game(Mario Kart 9???) plus Wii U ports Smash 4, Splatoon and Mario Maker (if they can get it working) then a new game every 2 weeks, with tentpole releases every few months (June, September and November.) which will include a new 3D Mario towards the end of the year.
3rd Partys
Ubi - Just Dance, Rayman, and Possibly Steep.
Capcom, - Monster Hunter, possibly a fighting game later in the launch window
Activision - Skylanders, Overwatch and Destiny 2 (with all of destiny 1 able to be played immediately by anyone who pre orders destiny 2 digitally)
Square - FF Something,
Warner - Lego Games,
Plus a few Japanese 3rd partys I'm forgetting like youki watch