I think Switch can sell about 25m in 2019, assuming they are able to manufacture and ship that much. Not sure how many the PS4 will sell though. I think Switch will be above PS4 by at least 10m though. So Switch by 10-15m.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox