If you said it would have more 10 million plus sellers than any other Nintendo system, I would absolutely agree. Without a doubt.

All systems though, Sony included, I don't know.
I think the PS4 is at around 11 already between the GTA V, the CODs (BO3 & 4, WWII), the FIFAs (17, 18, & 19), Red Dead Redemption 2, Spider-Man, God of War, and Uncharted 4. And we all know for a fact it won't stop there. I would guess that the next & remaining 10 million sellers will be, two more CODs, two more FIFAs, and Last of Us 2. Bringing the PS4's total of 10 million sellers to a whopping 16. The Switch has been an incredibly successful platform that has sold a lot of software, not just Nintendo's. But, at least 16 games each selling over 10 million copies? That's asking a lot. 

Like you said, it is a possibility, but it's mostly dependent on how well new games released on the PS4 sell moving forward, which given Sony's track record, should be very well. 

PS4 came out since 2013 and have around 11 games only? Switch isn't even full 2 years old and already have 5 games, well...

Edit: nevermind.

I think SMM2 will top 8-9M. I still don't see more than 9 ten millions sellers for the Switch and the only one which could be the 10th is a new Super Mario Kart.
Remember also that Majora's Mask had the same quality orverall as Ocarina, but sold twice less.

Also I live in a world where I believe that the Switch won't reach 75M because it will be replaced in 2021 by the 9th gen Nintendo hybrid next console.

You really thought that? That takes a lot of guts to admit.

Yeah after the debacle that was the Wii U and that January reveal where they spent way too much time talking about stuff like HD rumble ice cubes I was convinced Switch was another flop in the making. I'd grown so accustomed to the Wii U's pitiful sales and the Switch seemed so similar to it in so many ways (sharing a lot of the same games, having a patchy release schedule, being overpriced relative to its power, even looking like  slimmed down Wii U gamepad) that I found it hard to imagine it selling much better. 

I'm very glad I was wrong.

No doubt.

Guaranteed: Animal Crossing, Splatoon 2, Super Mario Maker 2, Pokemon Gen 8
Likely: Super Mario Party
Maybe: Minecraft, New Super Mario Bros. U Deluxe

AC
Splatoon 2
MM2
Gen8
Gen8/Remake
Gen9
SMP
BOTW2
SMO2
NSMBUD

AC  ==>   95%
Splatoon 2 ==> 80%
MM2  ==>  20%
Gen8 ==>   100%
Gen8/Remake  ==> 100% if it exist
Gen9  ==> 100% if released on switch
SMP ==>  50%
BOTW2 ==> probably not coming on Switch
SMO2   ==> 80%
NSMBUD==> 0%

Is MM2 Super Mario Maker 2? And if so why is that 20%

I would like to know your LT for SMM2