> users who disabled Telemetry would see this problem resolved even though the problem is not related to Telemetry functionality itself and could have been triggered otherwise.

All they mean by that is that it was a bug in their HTTP/3.0 code that could have been triggered by any HTTP/3.0 connection that was using that codepath. But the reason for that particular connection (which had the conditions to trigger the bug) was for telemetry.