These statistical inaccuracies often happen with StatCounter. Nothing newsworthy and no, users are not downgrading to Win10. November was a pretty good month for Windows 11 in fact, see the Steam HW survey for example: https://store.steampowered.com/hwsurvey
Up until the cutoff date, all my OS installs will be windows 10 - really not happy about the impending shift to 11. It’s really reminding me of the 7/8 switch - UI changes that are obnoxious and default, the settings app growing ever more labyrinthine, getting blinded by random driver and older software incompatibility issues.