I'm guessing it'll be higher than 20 million, but not much more than that. So I went with the 19-20.9 million option.
The Switch is still going to get a plethora of new games, big and small, most of which I think will be 3rd party. But as far as Mario is concerned, B-C tier spinoffs like another Mario Party, Mario Golf, Mario Sports Mix, or another Mario RPG (Whether it's a new Paper Mario, Mario & Luigi, something new, etc.) is all we're going to get. I think the big, blockbuster, A-S tier stuff like Mario Kart and the platformers are being saved for Switch 2. I fully expect Mario Kart 9 to be a launch title and the next 3D Mario game within the first year of its cycle. Once Switch 2 or whatever their next system is comes around, THEN I think we might see a brand new 2D Mario game... Assuming they haven't just replaced the 2D line with Mario Maker.
A port sells more than a new game.
Mario 2d platformer is different from the Mario Maker series. IF Nintendo doesn't know this then Nintendo is in big trouble.