30 years ago when the majority of the market was kids, sure.
The PC has had a similar kind of setup of never ending generation/no real generation dilineation for many decades too and has done well.
If you're selling only to kids it can be a problem, but the industry has grown up since then, even Nintendo's fanbase is majority adult today.
There's still no indication that third parties would be any more willing to develop for a Switch Pro than they are for the current Switch.
Bet with Liquidlaser: I say PS5 and Xbox Series will sell more than 56 million combined by the end of 2023.