Eh, all his predictions are very conservative.

It takes 20k a week to do a million a year (and that's not even including the holidays). With digital Splatoon probably does roughly 50k. That'll slowly go down, but you throw in two holidays seasons and by the end of next year Splatoon will probably already be at that 9.5 mil figure. Likely all of ninson95's predictions will have been exceeded during 2020, and the games will still have a few years left to sell.

Also let's not forget at some point all these games will be part of nintendo selects sale so they'll be down at $20 in a few years.

I guessed 23mil,22mil,18mil,12mil and I wouldn't be surprised if all of those get beat by a bit.

These are my lifetime guesses, Switch versions only, and I am assuming none of these games get a sequel on the Switch.

SMO: 16m
MK8D: 45m
BotW: 19m
Splat2: 14m

Mario Kart 8 - at my workplace - is probably selling Switches more than any other game because everyone wants to play multiplayer with us at lunch. I'm not sure how high it will go, but over 30 million won't surprise me in the least.

SMO: 16 million
MK8D: 30 million
BotW: 20 million
Splat2: 12 million

I expect Mario to continue to slow down but sell steadily. Mario Kart 8 will sell until Mario Kart 9 comes out on Switch 2. I expect Breath of the Wild to sell forever as well. Splatoon is still a growing franchise so I don't expect it to hit a big number like the others.

SMO: 17mil
MK8D: 28mil
BotW: 18mil (Switch only)
Splat2: 14mil

shipped plus digital sales

Odyssey : 17m - huge opening but legs are weaker than i expected.
Zelda : 15.5m - best legs in zelda history.
Mariokart deluxe: : 24m - will overtake odyssey soon and will move further away.
Splatoon : 12m - could reach this amount if there is no splatoon 3.

SMO: 18M
MK8D: 28M
BotW: 15M
Spla2n: 13M

This is assuming that the Switch will sell aproximately 100M lifetime and that these games don't get sequels in the next two or three years. Especially Mario Kart 8D's sales will depend heavily on the success of the Switch and whether or not we'll get an MK9, so they're hard to predict.

I can remember when people were saying that zelda breath of wild was going to be a 4 million seller like skyward sword lol.

I find puzzling how people are predicting Odyssey to sell 4m~7m more than Zelda BotW...

I mean, this year Odyssey shipped 2.1m versus 2.6m from Zelda. It's outselling Mario every quarter after the one it launched, and if Media Create is any indicative, things don't seem like they will change in the near future. Mario's legs are, surprisingly, weaker than Zelda's. So even if it ends up outselling it, I guarantee it won't be by much. xD

EDIT: As for my predictions:

Mario Kart 8 Deluxe: 35m

The Legend of Zelda: Breath of the Wild: 20m 

Super Mario Odyssey: 18.5m

Splatoon 2: 11m

I think many thought SMO will outperform BOTW in Q3 because of holiday months where Casual players > Core players and recover from Q1+Q2 against BOTW