The question is do they ever fetch and transmit it if you opt out?
The expected answer would be no. Has anyone shown otherwise? Because hypotheticals that they could are not useful.
Why? They are useful to me and I appreciate the hypotheticals because it highlights the gaps between "they can access my data and I trust them to do the right thing" and "they literally can't access my data so trust doesn't matter."
Hell, all the times they keep enabling one drive despite it being really clear I don’t want it, and then uploading stuff to the cloud that I don’t want?
I have zero trust for Microsoft now, and not much better for them in the past either.
One day they came in and found an icon on their desktop labeled “Where are my files?” that explained they had all been moved in OneDrive following an update. This prompted my clients to go into full meltdown mode, as they knew exactly what this meant. We ultimately got a BAA from Microsoft just because we don’t trust them not to violate federal laws again.