Pretty much most Nintendo development teams are likely working on NX software as we speak so it wouldn't be much of a surprise.
Have you guys actually gone back and looked at the software Nitnendo consoles get in their so called "fifth year"?
N64 from December 2000-December 2001 got Dr. Mario from Nintendo and basically nothing else (lol). Rare published Conker's Bad Fur Day. That was it. Two whopping games. If you didn't buy a GameCube for launch that's all you got.
GameCube from Dec.2005-Dec 06 had Odama, Chibi Robo, both outsourced games, and Nintendo picked up the Western publishing for Baten Kaitos (Namco) in the West. It got Zelda: TP, but only after the Wii got it first.