No shock here they have dropped almost all of their platforms like dead weight near the arrival and after the arrival of a new platform. The Wii U is pretty much unofficially dead anyway, so this does not surprise me.
The only exceptions I can think of to Nintendo dropping support almost right away are the NES, SNES, GB, GBA, and DS. All the other systems got dropped almost immediately for their successor (the N64, GCN, and Wii being notable examples).
Lifetime Sales Predictions
Switch: 151 million (was 73, then 96, then 113 million, then 125 million, then 144 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 57 million (was 60 million, then 67 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima