> You wouldn't need to send information to Mozilla to get an update or get CA revocation lists.

Any request to Mozilla is sending info to Mozilla, and thus should be covered under the privacy policy. Every check for an update likely also includes the current version running so they can send back info on whether the update is important/security related or not. Even if it was just a "list all versions" request, it still signifies that IP used the browser. Similarly, a CRL list update signifies that the IP used Firefox and that the conditions that trigger a CRL update were met (which might mean an HTTPS address was visited, or it might happen at startup).

Any time Firefox implicitly requests data from Mozilla, that's something that they would likely cover in their Privacy policy. Chrome got a lot of flack a few years back for essentially the same problem, but with a twist. Every time it started it would download a binary blob from Google. It turns out it was the code to do voice recognition, which was executed after download. Fairly innocuous if you trust Google, but it was executing remote code from Google on every startup, so people were rightly disturbed by what they saw going on until an explanation was put forth.