I think because of the shortages it's more likely than before that the Switch sells over 20mil next year.
But it might as well go differently.
For example, worst case scenario:
FY21 - 23mil
FY22 - 18mil
FY23 - 10mil
FY24 - 5mil
FY25 - 1mil
This scenario asumes Nintendo can't quite hit their target for this FY and also ships below 20mil next FY and then dies rather quickly. I don't see the successor releasing before March 2024, so this scenario is rather pessimistic and asumes a weak lineup in 2023 as well as quick saturation and no new models. And yet it's still above 140mil.
Best case scenario:
FY21 - 25mil
FY22 - 23mil
FY23 - 18mil
FY24 - 12mil
FY25 - 5mil
FY26 - 2mil
Granted if the successor releases in March 2024, 12mil won't make any sense. Also this scenario asumes that Nintendo still manages to ship 25mil this FY.
The only way the Switch can sell below 140mil is if the successor actually does release in 2023, which I don't see as realistic. And it can only realistically sell over 170mil if it's successor is not backwards compatible, which leads to continued high sales in 2024 or if it releases in 2025, which could be to late. The successor should ideally release when the momentum if the Switch isn't completely dead.
