Hope I'm wrong but since for now it looks like Nintendo is only one who's gonna do the the heavy lifting my answer is a generous one or two.

I mean. We don't even know what they have for next year. Even this year I can't think of anything other than Mario Odyssey.

EDIT: things could change though. Nintendo is like the wild card now. 

Well, Nintendo is bringing in a single year games that, in the past, were the main game for that year. A Zelda, a Mario Kart and a 3D Mario (plus Splatoon, but that is still too young). So at least those have to sell a million minimum. Most 3rd parties are "waiting", which translates to "I don't want to risk porting my game over there before the platform sells enough". Considering the WiiU, I can't blame them that much, but it's also a vicious cycle, because they don't help create that userbase. Nintendo has to be the one doing it during first year, or at least until A-AA japanese devs start bringing enough games to fill the gaps, and the rest might follows suit.

I still have no idea what Nintendo is planing for the future. Maybe they don't know either, but I feel like 3rd parties are coming when their console become super successful. 

Out of the games we know of so far:
Breath of the Wild (already)
Mario Kart 8 Deluxe (Probably did it at launch)
ARMS
Splatoon 2 (This could do one million on launch with just Japan alone!)
Super Mario Odyssey
Minecraft

so 6 for sure in my view.
I'm unsure about Fire Emblem Warriors.
I'm crossing my fingers that Xenoblade 2 will do it.
I dont see 1-2 Switch legging it out

I don't know about the West, but Japan loves that kind of game, its sales there have been great. Considering the eventual Splatoon 2 release, the userbase over there will grow massively. Also, it has done fairly well in Europe too, although it will lose its legs when more games start to appear. I think it will just barely made it.

5 or 6. i cant see too many huge AAA games all being ready for the first year. it will definitely get a lot more in its lifetime though

Zelda
Splatoon
MK
Odyssey
1-2 Switch
Skyrim
Xenoblade


Possibly: ARMS, Fire Emblem Warriors, Sonic

I expect a couple of third parties to achieve so my prediction is:

9 First Year

Possibly 13

I'll guess about 7.

Along with Zelda, I think we can count on Splatoon , MK8 Deluxe, and Super Mario Odyssey. Besides that, there are a lot of unknowns. Arms' level of success is a mystery, Minecraft may not quite get to a million this year, 1-2 Switch may fade after the launch window, and there are probably one of two notable games coming out in 2017 we don't know about.

- Zelda
- MK8D
- 1 2 Switch
- Minecraft
- Arms
- Splatoon 2
- FE Warriors

- Mario Odyssey 

minimum 7-8

- BotW
- 1-2 Switch
- MK8D
- Splatoon 2
- SMO

+ few more games, like Arms, Fifa 18, FE Warriors