Nintendo

I'd bet money that the next one has backwards compatibility. Afaik Nintendo has never made a handheld that didnt get at least one generation of backwards compatibility. Gameboy had several devices with backwards compatibility. Then the GBA had DS backwards compatibility for it. DS had 3ds. I suppose the 3DS didn't if you view it as its own thing rather than the upgrade to the DS. Also I'm ignoring the single game devices and the tiny pokemon thing.

I could see them at some point trying to separate handheld and console again just because handheld has been their safety market while they experiment with console. But I doubt now is the moment they do that. And I'm not sure how they do it. Maybe release the switch 2 then after a bit release a console that fits its own niche the way the Wii did (it was great for groups and feeling generally more physically interactive)? But what is that niche that a switch 2 doesn't also fill? Maybe something like the vita tv device? Budget non portable model. Or maybe a console that does a better version of the GameCube 3ds combo. It has more power and its own games, but also acts as a dock that can play switch and switch 2 games if you dock one in it. I dunno.

That being said, Nintendo has no debt and a ton of cash on hand. They can fuck around and not find out for like 30 years.