Considering the following variables are now highly likely to be true: Switch Revision this fall, Nintendo reloading their big guns (rumors of Metroid and new DK are now beginning to pick up steam), as well as the clear commitment for support past 2022, have you considered revising your current predictions for the Switch, if so or not, why?

I think I'm gonna wait a bit longer to change it in my signature simply because I've had to change it so many times already and the Switch has been the most unpredictable gaming platform ever in its sales. At the moment, I still stand by that it won't pass the DS or PS2. Basically I'm just not committing much to a prediction right now. 

Now I think the Switch will end up between 160 and 180mil. I'm convinced it will outsell the PS2.

I am not so sure about refiring the big guns. Yes, Splatoon 3 will sell a lot, mostly to people already having Splatoon 2. This will make Nintendo a shitload of money, and that is the goal for this release, but it will not sell a lot of Switches, as this games targets users already owning one. This is the main thing: sequels on the same platform do sell well and as they reuse effort from the previous game are cheaper, so they have more potential for higher profit. But they are less helpful to sell hardware. That is why 3rd-parties do that many sequels: they want money but aren't in the business to sell consoles.

I am unsure though about Mario Kart 9. While wildly successful, Mario Kart 8 Deluxe is a port/remaster/remake (whatever you like to call it). That usually has not the same sales potential. Now looking at the sales of MK8, this doesn't seem to apply here, so I am unsure how much new Switches a Mario Kart 9 might be able to sell.

In the same vein I see some Switch moving potential in a true new 2D Zelda. Metroid was never too big a series, but some Switches might be moved with that as well.

But there is one big hitter, that can move a lot of Switches which Nintendo still hasn't tapped into. That is a new Wii Sports. People tend to disregard it's success, as it was a pack-in with Wii. But looking at Wii Sports Resort, that sold 30M. And not for the Wii Motion Plus, which was supported by like three other games and could be bought without the game. A proper new decently made Wii Sports Resort could easily sell 30M again. And I see half of them selling to new Switch owners, to people that haven't owned a game console since the Wii. And they could even give Wii Sports the Ring Fit treatment, which wasn't just a new Wii Fit, but something more. In the last time I felt like a Switch Sports got less likely, but then Miitopia happened and now I don't know.

Why do you think Switch would be replaced so soon?? 2023 would be soooo early even if a new model wasn't coming out.

I do agree though that MK9 on Switch seems like a possibility now. Because I could see Nintendo trying to extend the Switch to say like 2026/2027.

This year and next year we already know to expect an upgraded 4k system, BotW2, two Pokemon games, Splatoon 3 and a handful of other large first party games. Basically the insane sales momentum of last year is still going and isn't going to stop anytime soon thanks to the new hardware and huge blockbuster games dropping in the next 6-12 months.

A new upgraded 4k model allows Nintendo to advertise the Switch as not seeming old compared to the newer systems, even as the Switch heads into years 6, 7, 8. They can probably keep the insane sales momentum going though 2022 with the mega selling games that are coming plus the new model. When sales do start dropping back down to like 20 million in 2023, they can easily drop the price of the Lite, and drop the upgraded model to $300 to replace the original if they haven't already gotten rid of the original by that point. Release MK9 in 2023 (along with a couple other big games / sequels we're waiting for - MP4, new 2D or 3D Mario) so it can have several years to sell before the Switch is replaced, and that along with price cuts will keep sales from leveling off too quickly right when Switch is starting to drop down from its insane sales years. Then in 2024/2025 you release another round of Pokemon games (gen 9 and Legends 2), a last couple other big first party game sequels and some smaller/neglected series, drop the Lite to "buy on a whim" price level of like $120, drop the 4k system to $250, introduce the Nintendo Select discounted games on all their older games. Then in 2026 they're mostly going off momentum of their huge userbase and let hardware sales naturally drop, maybe drop 4k system to $200 to help out, as they start focusing on getting the Switch 2 ready. Rumors of a new system start getting intense in 2026 and that Fall they announce Switch 2 coming in March 2027.

If they are planning on replacing the Switch in only like 2024 or early 2025 I don't see a need for MK9 on it. But if they are looking to extend Switch's life to 2026 or later then it makes sense to have a newer Mario Kart to lead the way in keeping sales momentum going into the Switch's later years so MK8D doesn't need to try to literally evergreen for a decade.

With a new model possibly on the way now and Nintendo highlighting this is only the middle of the platform's life I suspect we may see a return of the GBC approach where a newer more advanced model comes in and acts like a pseudo successor. If this happens then I pretty much think NS can become the top selling platform of all time. 

He didn't say though, that Switch 2 followed closely on the release of MK 9. MK8 was also more in the middle of the life of the WiiU and still got an launch window port on Switch. That might be possible again, even if the game is a few years old by then.

I underestimated Switch. It won't need non-gaming features or a $100 price point to become the best selling console.

Switch will be the new King as long as Nintendo doesn't do something crazy.

Here is something to keep in mind about 3DS sales.

2015  7.33m
2016  7.59m

The 3DS actually went up YoY in its sixth year.  This is pretty impressive for a system that peaked long before this and was ready to receive a successor.  Most systems would get a pretty significant YoY drop at this point.  One big thing driving sales in 2016 was the release of Pokemon Sun/Moon.   The 3DS already had x/Y and Alpha Sapphire/Omega Ruby, but another Pokemon game still ended up increasing sales YoY in the 3DS's sixth year.  Big releases still drive sales even if the franchise is already represented on the system.

Switch still has several Pokemon games that are yet to be released.  And of course Mario Kart 9 would be huge.  It's true that a new Wii Sports or 2D Mario would also be significant releases, but Switch actually doesn't need them.  After 2021, what Switch needs is simply to keep YoY sales from "falling off a cliff".  It could probably do this simply off of third party releases at this point.  The quality and quantity of third party games increases each fiscal year for Switch (including this past fiscal year which had to face game delays due to COVID).  However, Nintendo isn't resting on their laurels either.  We already know Splatoon 3, BotW 2, and several Pokemon games are still coming.  I also think Mario Kart 9 is likely to get released.  These sequels drive sales too, even though they already have a franchise on the system.

A full fledged AAA 2d Mario is a killer software. Don't underestimate his power.