At this point the only thing that can stop the Switch outselling the Wii is Nintendo.
If they keeping going the way they are and support the system properly, it will pass 100 million.
They only way it won't is if they go full moron and cut it short prematurely.
Bet with Liquidlaser: I say PS5 and Xbox Series will sell more than 56 million combined by the end of 2023. (And over 130 million lifetime)