While the inclusion of F-Droid can be discussed:
against: there is an official app store “Apps”, having two may be confusing;
pro: with F-Droid we are guaranteed to have only open source apps, whereas in “Apps” it is not obvious. (This is why I also suggest including F-Droid)
However it would be really nice to have F-Droid Priviledged Extension allready installed as system app (like Fairphone Open OS and Lineage with microG both do). Thus any casual user that installs F-Droid will be able to have automatic updates from it.
On the opposite it is really impossible for such users to install the F-Droid Priviledged Extension as system app (requires TWRP…).