I see what you mean but it's entirely possible to skip a gen. If Sega released a console for the first time since 1999, it wouldn't be a gen 7 machine. It would be gen 9 along with everyone else.
I still say the Switch is gen 8 but if Nintendo released 3 systems (gen 9,10, and 11) and Xbox/PS only released one, one could argue that they just sat the generation out. Just playing devil's advocate, here.
Precisely. There seem to be a few people saying the Switch is a 9th Gen system because it succeeds an 8th gen system, but it just doesn't make a whole lot of sense to define what generation a console belongs to, solely based on the generation of it's predecessor, when you start encountering the issue that I highlighted, and some companies could straight out take a 20+ year break as you just highlighted.