As mentioned above, simply forking may not be sufficient. F-Droid.org has clearly adopted a more stringent and cautious approach.
I believe this is reasonable, as I stated earlier: downstream projects have no right to freely use the upstream’s name for promotional purposes.
However, I think that’s where it ends. Developers’ rights on F-Droid are limited to publish permissions, downstream names, and downstream IDs.
Additionally, I don’t entirely agree with the casual comparison between F-Droid and Debian. F-Droid has no obligation to deliberately preserve this software.
Debian is an entire operating system, while F-Droid is merely an app distribution channel, removing a few apps won’t cause significant disruption.