On the one hand good on the brand for being able to have a variety of market conditions, internal and external, to allow them to make such a claim. The numbers don't lie.
But those numbers definitely come with some caveats, which you aren't going to get from Nadella in a Twitter post. We know about the rumors Microsoft paid for chip priority probably around the summer of last year, when they were stocking up Azure servers with Series X blades to revamp some stuff with GamePass. We know they have less global markets to satisfy demand for, meaning less consoles in those markets they need to supply. That allows them to pump stock into the few markets where demand is particularly high for the product, America being one of them.
When you've already got a limited amount of systems to supply, having the majority of your demand concentrated in a small handful of markets is a hidden benefit. But something else to keep in mind is that MS seem to be ramping down hardware sales forecasts. I don't know how long, how many quarters that's for, but comparatively, Sony have their supply shipments set up and they're pretty much expecting to make up for the shortfall earlier this year with H2, in Q3 & Q4 especially. And, I suspect that'll allow for a lot more units to NA (hell, it's to the point I may be able to easily pick up a system through PS Direct, tho I'm holding out for a non-bundle).
So yeah, good play on MS & Xbox for being smart with their supply and having enough in NA to take the last few quarters in terms of next-gen console sales. However, I don't expect it to last much longer and most people are probably of the same mind.