In fact, uBlock Origin is one of the officially recommended extensions by Mozilla
uBO Lite was incorrectly flagged as violating policy by someone at Mozilla, but rather than appeal that decision in any capacity at all, the developer just removed the add-on entirely without responding to Mozilla. The original decision was almost certainly just an error.
I dunno about the iOS version, but on the desktop and Android versions both you can also disable them directly from the new tab page itself.