Good point, I’m assuming Mario to greatly outsell Zelda each holiday, but we’ll see.

I personally don't consider SMO a game for casual players.  You may be right though that it will sell more during the holidays.  We'll see.

Mario Kart 8D- 25 million if Mario Kart 9 doesn't come to the Switch, which I'm thinking it won't. Could be as low as 18 million if they do release another Mario Kart.
Odyssey-21 million, again if there's no sequel, but that's hard to say. Galaxy got a sequel, so it's possible. 17 million if it does, as most of its sales are already locked down, so it shouldn't have trouble getting that.
Zelda-18 million, again, assuming no sequel on Switch. 15 if it does, as again it already has over half the sales it needs to get to 18 so cutting that short shouldn't cut off too much.
Splatoon-10 million, and I'm pretty sure there won't be a sequel on switch, but it won't make much of a difference. This is a series that has potential to do 15 million plus, but Splatoon 2 didn't evolve the series enough. It kind of felt like they rushed it for Switch's first summer, and it should have launched this year with the Octoling expansion included, and a bit more freedom in the multiplayer.

Of course this is without seeing how Switch does this holiday. If it really slows down, I might have to adjust this down, but things are looking good so far.

I agree with you on this. Breath of the Wild is going to surprise a lot of people. It's the mascot/flagship game of the Switch and is going to keep selling decently for the remainder of the generation. We'll know a lot more in about 4-5 months.

There is going to be a fifth evergreen title: Super Smash Bros Ultimate.

This is very hard beacause we dont know how big install base Switch will have at end and when we could have next 3D Zelda and Mario, or maybe MK9 that would definatly effect sales.
But going buy current numbers and sales, I would said something like this:

-SMO: 17m+
-MK8D: 20m+
-BotW: 17m+
-Splat2: 12m+

And yes, soon we will have Smash Bros in that list also. :)

MK8D: 27M
BotW: 18M
SMO: 18M
Spla2n: 11M

Splatoon 2: 10.7 million

Mario Odyssey: 17 million

Zelda: 14.5 million

MK8: 20 million

Interesting how few people thought that MK8D would reach 30mil and that BoTW would reach 20mil. Even tbone lowballed it . They were pretty spot on about Splatoon 2 though.

MK8D: 51mil
BoTW: 32mil
SMO: 28mil
Splatoon 2: 13mil

We really don't appreciate how well Nintendos Switch games are selling. With years of sales still ahead of us all those predictions will all be way too low. 

MK8D: 55mil
BoTW: 38mil
SMO: 26mil
Splatoon 2: 14mil

Is there any extensive data how Nintendo games were priced over time on consoles like Wii, DS and 3DS? How much of the sales generally are in the period where games are Nintendo Selects?