No reason to wait 
F-Droid allows the installation of two older versions (even more with enabled Archived repository):
- “We” are not related to or working for the Nextcloud GmbH, but a independent group of volunteers which have fun in programming
- We have thought about this, and the benefit of pushing updates directly is interesting but nothing compared with the drawbacks
- Hosting infrastructure (costs money & time)
- User adoption: The amount of people using F-Droid is tiny compared to Play Store. Adding an extra barrier by requiring an additional repository to the default one will decrease the user adoption for no reason
- It is actually a security benefit that we get the app from a completely independent build chain and adds trust to the Play Store: You can compare the builds of those two binaries. I as an user trust F-Droid more than most of the app sources themselves and therefore that the distributed package is equal to the source code
- F-Droid will probably not remove the app from their catalogue (and that’s fine), this will just add an additional release channel which we have to maintain
- Having this kind of problem is not nice, obviously, but after years without any bigger issues, this is no reason to change distribution process
I guess if one wants to improve the F-Droid experience, one could donate to their infrastructure and resources, maybe even rethink the pull concept and contribute some architectural ideas and / or code 