I don't think Windows 10 is sending off personal data-- but that's based on me and others sitting there running tools like "Wireshark", then inspecting the results; it's not totally conclusive since it's not like I logged everything for weeks-on-end-- heck, I don't even run Windows for those kinds of durations, as I do 99% of my work in Manjaro Linux these days. But the point is, to make the claim that Windows "respects privacy" requires some kind of independent, third-party audit.

Then you get to people like this fellow, who asserts "Windows 10 respects privacy because Microsoft put little toggle switches into the control panel." Yes, but how do you know they do what they claim to? In GNU/Linux, I can independently look at the source code and see exactly what configuration GUIs and scripts do. But in a closed-source proprietary OS, simply saying "company XYZ has a control panel which does ABC" is almost totally non-verifiable.