The fediverse is not a platform but a set of protocols. Nobody can force you to federate with an instance any more than they should be coerced to listen to anyone's speech.
F-Droid isn't a platform either, you can run your own repository where free speech is priority if you want and offer your own version of F-Droid that comes with your repository compiled in as default.
F-Droid too is just a set of protocols. The default app is open source as well and you're free to modify it if you want.
I have no problem calling it a ban, I just disagree that this is a restriction on your rights or anything since you can just go elsewhere where the ban isn't in effect to do what you want.