Statcounter is... a valid proxy, but I don't know if I trust it for fine grain changes. Big trends, maybe. Windows overall certainly seems to have lost some ground over time. Whether that's desktop PCs becoming less popular, the laptop market moving a bit towards Mac, the handheld market being weirdly represented because this only counts devices used for web browsers or whatever else is harder to parse.

They officially changed the name in 2016. I have to assume they changed what the browser reports earlier this year. For tracking purposes it would probably make more sense to count the ARM version separately from the Intel version, but I don't know if that's correlated to this change or what is. I'm not a MacOS user, though, so maybe the change is public knowledge and I just don't know about it.

statcounter checks user agent strings. it probably depends on the mac browser used to report the user agent string.