I'm very curious to see what Ring Fit Adventure will do this holiday season. It's already turning into a sleeper hit, but at this rate, it could become a killer app for the holidays, especially for parents and other adults who can't afford a gym

At this point, I am not sure what Switch will sell this year, because I think they will be in short supply.  All of our calculations are based on figuring out demand.  What about supply?  How do we know how much Nintendo will manufacture?  We don't.  

I say this, because Nintendo has stayed with their very conservative 18m for the current fiscal year.  Even without the wildcard Ring Fit Adventure they were going to sell more than that.  The last half of the year has been full of hit games plus a Lite model.  I can say that in North America what is happening is that there are a ton of kids out there that have been begging their moms for months for a Switch because of Mario Maker 2, Link's Awakening, Luigi's Mansion 3 and most of all Pokemon (not to mention Mario Kart, Smash Bros, BotW, etc...).  And all of these moms have had to say, "wait til Christmas" about a million times.  Now that they can buy their kid a $200 Switch that will shut them up they are definitely going to do it.

So I think Switch is going to be in short supply in Japan and NA these holidays.  Europe should be fine, but in the first two regions Switch is going to be the "must have" item this holiday.  Nintendo is being too conservative, and I think supplies will be too short.

Nintendo's production is prepared to ship more than 10m units in the holiday quarter if that is what is needed due to high demand. Unless you expect them to clear the 18m target for the fiscal year by the end of the holiday quarter, you have no reason to worry.

I actually think they are capable of hitting the 18m target by the end of Dec 31, 2019.