Thanks. I haven't downloaded it to check, but from the GitHub issue I mentioned above that repo just contains a copy of the official Mozilla .apk, which contains com.google.android.gms and com.google.firebase. So it's not so good for "de-Googling".

I'm a lot less interested in the mechanics of using F-Droid than I am in the no-malware guarantee that F-Droid effectively provides.