Hum not true at all. Sales are really good overall on the last day of december.
Even the Wii in extreme shortage would be doing 150k better than Switch while the Switch is outselling it pretty much everywhere in the world. Maybe the numbers are right, but it would be the weakest last week of december i have ever seen and its not like the market isnt healthy...
PS4 did not that well in December so maybe the numbers are real, but Switch i really doubt.
Edit : I'm dumb and sorry lol just checked passed numbers and it would not be that terrible...
wii is a totally different beast then switch if you research correctly you would know the only reason switch is ahead is because wii had no supplies for its first launch holiday, while switch was fully stocked for its first holiday, wii was doing 450-500k on NPD on regular months like october. for the past 5 years January sales for consoles has been very very slow.