End of 10 is a campaign to move people over to Linux with Windows 10 support ending
(www.gamingonlinux.com)
Linux users are, as a group, less likely to share accurate telemetry and to masquerade as other OSes
I'm going to assume you meant "more likely" on masquerading, but I do want to point out, Linux users also tend to be more proud of their choice and to want to contribute to the statistics, want to be represented. Maybe those numbers effectively cancel out, but I doubt they significantly lean towards underrepresentation for the reason you mentioned.