Switch has been 23% down YoY after the first 2 months. To reach 18 million it would now have to be only 3.9% down for the remaining 10 month period. I think that is very unlikely.

Personally, I still think the Next Gen Switch doesn't come out before 2025. I also think that a 2D Mario will come out this holiday season. It will definitely boost Switch sales, even if it will be a launch title for Switch 2, plenty of parents will be just fine to buy their kids an old Switch with the 2D Mario. On top of it, even if Switch 2 is already out, the old Switch will still sell in the millions for surprisingly many years and therefore will trot to past 160 mil.

160m is very plausible at this point tbh the platform can get well within range of DS and PS2 by the time a successor arrives and then leg its way to 160m, 3DS after all went on to sell a further 10m after Switch launched, it may not even need that however given it's current momentum as a decent year this year and an average one next year can actually see it close in on the milestone.

3DS benefitted in two ways that allowed it to keep selling. The Switch did not play 3DS games and a 3DS model (2DS) was as low as $79 RRP, less than a third of the price of the new console. So a different library and a very different price bracket meaning Switch didn't make the 3ds redundant. Assuming the next console is the Switch 2 and it is BC I expect Switch sales to fall very quickly once it's successor is released. Just like the PS4 I don't believe we'll see a significant price cut for the Switch at the end of it's life, especially while we are currently in an unprecedented situation where console prices are actually being increased and Nintendo will want to strongly push their new hardware as a direct replacement of the Switch.

Assuming no new Switch model, no significant price cut and Switch 2 in Holiday 2024:

End of 2023 = 137m
End of 2024 = 147m
Final Tally = 153m-157m

They absolutely can break the 160m mark if they release a new model, substantially price cut or don't release the successor until 2025 but currently I'm pretty confident none of these three things will happen.

Basically the ball is in Nintendo's court, they could get the Switch to 160m easily, but I believe they'll focus strongly on quick adoption of their new system rather than using promotions to eek out a few more million from the Switch.

We'll at least find out if there's a new model coming in the June direct, I imagine if there is one final hardware revision coming after all that's the date it'll be announced.

if they take a long time to launch a successor (Q4 2025 or beyond), 160 million is quite likely to happen.
If they launch a successor between Q1 2024 - Q1 2025 (so in a 5 quarter range) which is super likely, 160 million is tough.
DS was the best-selling Nintendo platform of all-time, and sold under 10 million units after the 3DS launched in Japan (and shortly after in the rest of the world). Keep in mind that the 3DS screwed up its pricing, lack of an eShop right at launch, and some early software misfires, and the DS still didn't capitalize on that in a massive way.
While the Switch and its successor will not be identical to the DS to 3DS transition, it's unlikely that the Switch sales are above 10 million more units after its successor launches.

Zelda + Mario will push this to 145m March 2024
Metroid and final releases in 2024 will push Switch to 160-165 M

With Switch being around 20-25% down each following year after 2020, I don't see Nintendo waiting till 2025 to release a successor.

They will announce it probably by the end of this year, and they will release it either holiday this year or spring next year.

Historically, after 1 or 2 years at most after the peak period of a system, Nintendo always releases next system. Now it's gone even further. However it won't be infinite.

I expect Switch to finish at around 135M this year, and with successor on the market next year, I expect Switch to finish 2024 between 142 and 145M at max.

Doing totally Lifetime no more than 150M.

Generally before a console announcement a lot of rumours and leaks happen in the months before. At the moment there has been very little said about a switch successor so I feel like this year is unlikely next year maybe.

Honestly, if Switch breaks 15M this year and a successor isn't announced until next year, I believe it still has a shot. Here is what the Switch would be at if it follows a similar trajectory as Wii, which many believe declined rather quickly

End of 2022: 122M
End of 2023: >137M (15M)
End of 2024: >147M (~10M)
Lifetime: >152M (~5M)

I'm using FY data for convenience. But Switch's 2022 appears to be comparable to Wii's FY 2011

Yeah. The leaks about a potential Switch successor launching in this recently started fiscal year are pretty slim and could easily be fake. Nintendo would have to be super good at hiding dev kits, images, and other things if the next platform is already out in Q4 2023. 

Switch may have only been officially unveiled on October 20, 2016 (less than 5 months before launch) but Codename NX was confirmed in March 2015 and the March 2017 release date was confirmed in April 2016. That doesn't mean the next system is still 2+years away, but rather that we have to hear something. And it seems the only reason Nintendo confirmed NX so early on is because the 3DS was already 4 years old that point and the Wii U was a failure that would've been really tough to turn around at that point. 

It's against Nintendo's interests (I would think) to announce a new system is in development (with a codename or unveiling) too far in advance. The Switch is declining year-on-year but has still been a a mega-hit. 

Whether Switch hits 160 million or above, I'm pretty sure 2023 is the last year it sell 15 mililon+. And if the successor launches in the first half of 2024, Switch probably won't even sell 10 million in 2024 (see my earlier post about sales decline for even the DS when it was replaced).