Just for clarification sake, opt-in telemetry is still telemetry.
Even if it's opt-in, just the fact that telemetry exists alone is alarming, as it opens a new hole ready to get raped, I mean exploited.
However, Windblows users are already used to having telemetry, they already got conditioned into loving to be spied on all the time, so of course they will accept telemetry everywhere.