Nintendo most likely shifted to NX some time ago...especially if the dev kits are already out there. Whatever Wii U projects were in the works have shifted to NX. Just because the games aren't announced doesn't mean they don't exist. It's likely that next year would have been the second round of Wii U games from some Nintendo devs, like Retro and EAD Tokyo. Instead, now those will be the launch titles for a new platform.
Question is, how easy is it to bring that unannounced software to a new platform. I'm expecting the initial launch games to essentially be Wii U ports (as in, games that were built for Wii U but have been moved to NX). If the NX is significantly more powerful than the U, perhaps this could even speed up development.
So, I see no real reason to think that Nintendo doesn't have enough time to get games ready to launch for 2016. Zelda, 3D Mario, Retro game, Pikmin 4 are all strong software that could easily be ready by next year. Along with perhaps some other games that have been in development but were not announced because Wii U flopped and they have been moved.
Where the trouble most likely comes in is after the initial wave of software, when Nintendo begins building games built for NX and runs out of titles that are essentially Wii U up ports.
