I think all of the following will have a huge chance:
Zelda
Mario Kart
Mario Odyysey
(shockingly) 1-2 Switch has already shipped 1 million apparently
Splatoon 2
Skyrim
Minecraft
if Xenoblade 2 launches this fall I think it will have a great chance of doing well, Switch owners will be hungry for a big adventure game
that's 8 that I'm fairly confident will pass a million by next March, most of which will do it at launch
then there's a massive chance (but obvs uncertain) that the following games come close:
Arms
Fifa (2017? whatever EA was referring to)
then possibilites:
Bomberman (shocked to say this but I in no way expected it to be at over 500k this quickly, might have more appeal than I realized)
so I honestly think there's a fairly decent chance that the Switch has like 10+ 1 million sellers have only a year. Pretty remarkable considering it will only have had one holiday season then... but quite possible. I think Mario Kart, Zelda, Odyssey, SKyrim, SPlatoon are all shoe ins. I think Fifa (particuarly because of PAL/Europe), Minecraft, Arms, and Xenoblade may all do great as well.
all it really would take is a few surprise popular third party announcements at E3 that come out in the fall and they're there at over 10 one million sellers. Bear in mind if someone like Capcom announces a Monster Hunter or Yokai watch like game, that's a guranteed million seller. Or even hypothetically if Nintendo randomly has a SMash port for the fall or some obscure Pokemon game. I think there are just a lot of possibilites to get a few more million sellers. The Switch fanbase so far has been seemingly buying a lot of the games that come out, with Snipperclippers and Bomberman having surprisingly great sales
