Given Firefox's pro-privacy positioning vs Chrome [1] and the fact that, by virtue of being in about: these requests get sent even if the user is browsing in private browsing mode or has extensions installed explicitly to block this kind of traffic [2] it's surprising the Mozilla employees in that thread are so keen to dismiss this.
[1] https://mobile.twitter.com/meatcomputer/status/8813107782251... [2] https://github.com/mozilla/addons-frontend/issues/2785#issue...