That probably counts as a privileged page, as in something uBlock Origin can't access or modify.
Mozilla has probably been running another "experiment", meaning not every user is affected. In the past they claimed it's not advertisements because they are "continually looking for more ways to say thanks for using Firefox". (Bullshit.) If you go to Settings > Home, you disable anything you don't want to see, or just set your home page to a blank page, period.
The "Arch cult's" holy book, the ArchWiki, states the following pretty clearly:
Mention of one's use of the AUR for their needs doesn't need to come with a disclaimer.
People who don't read or don't use their brain are going to keep not doing so, regardless.