I think for sure there will be at least these 7:
Mario Kart 8 Deluxe
The Legend of Zelda: Breath of the Wild
Super Mario Odyssey
Splatoon 2
ARMS
1, 2, Switch
Minecraft
Some games that I think are possible to sell 1 million in the first year are:
SnipperClips
Super Bomberman R
Fire Emblem Warriors
Xenoblade Chronicles 2
The Elder Scrolls V: Skyrim Remastered
Fifa 18
Fast RMX
Sonic Forces and Sonic Mania
But yeah at the very least there should be 7, but I would guess like 9-10 or maybe over 10 considering all the possible stuff that hasn't even been announced for Switch yet. (Such as what may be announced at E3).