This is from a year ago, but I didn’t see this level of persistence in gathering telemetry before. I am blocking most mozilla tracking endpoints via host file, but that’s a bit extreme.
Apparently you can create a custom preference to block it:
The good news is that it is possible to turn off telemetry-coverage if you are one of the lucky 1% selected to have it installed. To do so, you need to manually create a preference to opt out of Firefox telemetry antics a second time. Information on how to do so isn’t so forthcoming, either. It’s buried in the bugtracker for the telemetry-coverage system add-on but has been tested as working by Mozilla’s devs:
That was my first sentence :)
You seem to know a lot about firefox development and I agree after reading your comment that the source is not bulletproof.
ghacks has an even older article : https://www.ghacks.net/2018/09/21/mozilla-wants-to-estimate-firefoxs-telemetry-off-population/
I will look further into the issue.
Regarding “Mozilla is not an ad company and has no incentive to abuse it”, their current business model is selling space on their search engine list, so I would say they have incentive to conduct unwanted data collection to sell that 500M spot.