I think this will not be true and is a bit unfair towards /e/: they have already made their launcher available on F-droid, so i think it is reasonable to expect there will be others. I think the reason this has not happened so far is A) because of limited time for the small /e/ team, B) because the default apps are still all system apps, and so the team is unsure if/how they would work on Google’s Android. But the team is planning to ‘un-system’ the default apps, so they can be de-installed, so i think that when that happens, it is likely the team will put the apps on F-droid.