It has a shot at it.  I definitely think Switch will do at least 4.5M.  Not sure how far it is going to get above that though.  

I also think that Nintendo is likely to have supply issues during the holidays.  Who knows if there will even be 4.8M available to purchase?  They predicted 18M worldwide for the current fiscal year and they are going to blow right past that.  Nintendo seems like they are underestimating demand for the Switch.

Probably more that they didn't want to risk having to lower the numbers again, as that's poison for their stocks.

My apologies for the delay. I had a LOOOONG day at work today and just now got home. But, I've known about the update for a while since before I left.
Dragon Quest XI S: Echoes of An Elusive Age - Definitive Edition (Holy Shit, that's a long title) has finally arrived for the Switch and it has had a great affect on base Switch hardware sales. While the Switch altogether is down from last week, it was a very strong hold from the Switch Lite launch.

In just these pas two weeks, the Switch has nearly doubled its YoY advantage over 2019. October should be quite the big win for 2019. If the combined momentum of the Switch Lite and Dragon Quest is strong enough, it's possible for the Switch to build its lead up to 1 million units before the Pokemon arrives. Time will tell.

Just posted Week 40 numbers and the combination of post-DQ11, launch hype starting to wear off for the Lite, and increased taxes have led to a considerable drop for the Switch this week.

Really ? sales are less than half of the last week, I really don't believe this is because of the tax which actually affects the prices in a minor way, it is not like if everything was suddenly 30% more expensive.

That's why I mentioned the taxes point last and brought up Dragon Quest and Switch Lite first since those are the bigger factors.

Without the tax, sales wouldn’t have been as high last week, as people prepurchase items in advance. Last time there was a tax increase, there was a mini recession I believe. So yeah, there was an effect but it won’t last long 

Week 41 numbers just posted; Another steep drop as the Switch is almost back to the same baseline it was before the Lite launched.

That is due to the typhoon that hit over the weekend.

Just added Week 43 numbers and I have some calculations.
At this point last year, the Switch had sod through exactly 56.7522631% of its 2018 Yearly total in Japan.
If that percentage holds for 2019, the Switch would finish this year with 4,912,516 units sold in Japan.