I was kind of hoping Switch sales would hit 200k+ this week, especially with reports of lotteries being used. The low supply might have been out of Nintendo's control. That is a reasonable explanation. Although this is Nintendo, and I could also see them underestimating demand, which they have been known to do.
What is the cause of the increased sales in Japan? Are those that never owned the system buying it to play all past games they missed on gamepass, or are they buying it for the future games that will be coming to the system? I don't read all of the weekly famitsu sales charts has there ever been an Xbox X game on the top 30 sold list of any given week? Even Playstatoin 5 games rarely crack into the top 30 list for more than a few weeks before Switch games from 4 years ago passes them by on the weekly charts.
I think that is exactly what is going on. People who bought the X1 back in 2013 had a very limited catalog of games to play on it, but this time around, people who are new to the Xbox ecosystem have instant access to thousands of games from different generations. You add GamePass to the mix and Xbox is suddenly a no brainer for new gamers who still don't have an alliance to one platform, or to be used as a secondary platform.