I very strongly feel like this really should be opt-in instead of opt-out. They seem to want to do things the right way, but having opt-out telemetry in a password manager is something I really do not want.
To further anonymize the data and increase user comfort, cycle the selected users daily so the same user's telemetry is not collected multiple days in a row. That limiting of data collection may also make it more acceptable to some users. For example, it may be more acceptable if telemetry data were collected no more frequently than one day per month or one day per two weeks.