I feel like this just confirms what I have been thinking. When PS4 won 2017 in total sales people were out champing it like that was hard for it to do ... even though it only won because of stock, pricing, and a two month headstart. When Switch has "regular" weeks people talk about how its gonna fall of a cliff...
The point is that the Switch looks pretty normal sales wise when it has these down weeks. January might not be the best example, we'll see in February. But most doom evidence is pretty premature. Im open to the idea Switch will fall off though.