That isn't confirmed.
But not necessarily true. Here's the actual facts we know:
1. Wii 2007 did about 350k in 7 days at BF.
2. Wii 2008 did over double that, about 800k, in the comparable period.
3. Switch 2018 did more than Wii 2008, comparing the 5 days from Thanksgiving to Cyber Monday.
Combine 1 and 2, and you'll see that Wii 2008 could easily have been under 800k. For example, 335k in 2007 and 770k in 2008 (~2.3x) matches both statements.
Switch at 775k for this year reporting period would then meet statement 3. But in fact it could be even lower, because it's a 5-day period rather than a full week. So if Wii 2008 did 770k in 7 days, maybe it did 625k in the peak 5. So Switch this year could then be, say, 666k and still make all the statements true.
None of that is confirmed either, of course. The point is that Nintendo's previous statements are estimates with very few significant figures, so we can't use them for precise comparisons of any kind.