If it keeps the drop in sales YoY for this year and next that may not happen.

I didn't say that it would, just that it is possible. A lot will depend on how Microsoft handle the rest of the generation, and whether they decide to give up on Japan in particular.

Rough start for Warioware: Move It. It's less than half of Get it Together and while it'll be a better launch that Gold when factoring in digital that was a really late 3DS game so its sales were more acceptable. The series should attempt VR at some point since that would be a more unique entry. Also hopefully the PS5 makes up for the past few weeks at least somewhat the next couple.

I din't see anything MS could/would do to change this by a relevant margin.

I mean, it shouldn't take a big change to eek out another 500k over the next 5-6 years, they could get there just by crawling slowly forwards.

What make you think they will support Series in Japan for another 5-6 years? They didn't support X1 for 8-9 years, and well even their last year or couple years of support the sales (WW) were quite low.

They are a little over 500k now.

If they can continue to sell around 100K per year for the next 3-4 years, they may get there - to 1M.

So they even don't need 5-6 years for the 1M target.

But the 360's 1.66M is another thing ..

LOL, PS4 above PS5 in late 2023.
Sony really planned things well, huh? 🤣

Aren't xbox sales also dropping YoY in Japan? Why expect it to keep over 100k/year for the next 4 years?

Why not ? it should keep some baseline at least .. It is still having some weeks of 3-4-5k here and there, so there is possibility to at least keep around 100k per year.