Yeah, I think it's likely that Nintendo is trying to reduce the number of units in transit to make way for a new model. It's definitely not overtracking: In their investor presentation, they acknowledged that sell-through in the March quarter was 35% up YoY in Japan/North America/Europe.
So even more weird...VGC tracked +26-27% for sales to consumers from 2018Q4 and 2019Q4, and Nintendo tracked* even much more.
*No offense to VGC, Nintendo's tracking methods might be even more accurate.
If I just apply a coef x1,35 on the last adjusted VGC 2018Q4 sales, I get this :
Current PB on Secret of Mana remake : 2h27 (2nd)
Strongest worldwide achievement on TGM : 1st European S13 rank
Fastest TGM3 MASTER in Europe : rank Master V in 5min10
Western record on TGM3 EASY : 1484
Current PB on Power Ranger (Game Gear) : 10min06 (World Record)
Non-geek activity : ThermalHungary