I would say 8th gen. because I dont see the switch as a succesor of the wii u, but as a consolidation of the current handheld and home console nintendo where offering.
To elaborate, I say games define a generation or what games are capable during that generation. The capability's of the switch are pretty much the same as wii u so the games are very similar. The same as why the x1 and x1x are the same gen even though one is 4x the capabilities, the games are the same and neither does anything the other cant, just higher resolution.
Now the switch was barely getting some very few if any games the ps4/x1 where getting, I would assume its not gona get any game at all that comes from here onwards as its no longer a resolution issue anymore. It will be limited by things like ssd, raytracing and what ever does differentiate the gens.
It takes genuine talent to see greatness in yourself despite your absence of genuine talent.
