I'd argue this statistic is easy to manufacture when Nintendo console sales are generally artificially limited by their production rate. Is it that the Switch is the most immediately desirable system in Nintendo's history, or just that it's the most quickly produced one in history?
Possibly it's that the last Wii was such a dumpster fire, and people are desperate for a Nintendo console that is close to modern capabilities.
The hit Nintendo took by selling an underpowered console was loosing 3rd party support, as it was reportedly too much effort for folks like EA to support a platform that was so far behind their other supported consoles.
I wonder if history will repeat with the next generation of xbox/ps around the corner. If switch sales continue at this pace, I suspect not.