I think it is possible, but I am with the crew that says a “professional” Super Mario Bros would sell much more and that 10 million is a big stretch for Maker. Check the 3DS sales - I know Switch is more of a software monster, but 3DS and Wii U Mario Maker sales are just about dead even, not the same for Super Mario Bros. or Mario Kart.
I will add that Nintendo needs to revamp the formula if and when they do a Super Mario Bros. 9. New sMB is stale and smelly like month old bread. New graphics, new soundtrack, new story, new worlds, new level design, new enemies, new power ups. Like we used to get with every Mario game. Like Super Mario 3D games usually get.