Well, NPD is a for-profit organization, and they get their revenue from the businesses who are subscribed to their reports. They're not going to loudly announce negative news about their own customers. I doubt that they'll announce it when Xbox One falls behind Xbox 360 next month either.
No, that likely is something that NPD wrote. They said something similar in the report for December 2017.
Yeah, that will explain what i'm saying. NPD usually is very impartial, so is not that i'm against them or anything similar, is just that i don't want them falling in PR bullshit too like other companies.
And, yes i'm saying all of this because NPD indeed said the same thing last year, and now we know what happened during 2018. So we'll hear again in December 2019 that Switch "have become" the fastest selling console of the gen again then?