[lurtbancaster]

Mozilla presumably collects this operating system version data on new installs of Firefox upon first run.

I wonder how the analytics of Firefox forks are tracked. If they can even be tracked.

Tor Browser, LibreWolf et al privacy friendly forks, block Mozilla's data collection on startup and they spoof the user agent to Windows NT 10.0 regardless of if you run them on Windown 7, 8, 10 or 11.