Since this is going to be enforced through Google Services custom ROMs like GrapheneOS will not be affected. Of course if F-Droid no longer exists, that means we lose the largest centralized repository of open source apps which is a huge blow. There are other ways of installing and updating open source apps like Obtainium. But the big thing with F-Droid is that it also provides discoverability.
Since this is going to be enforced through Google Services custom ROMs like GrapheneOS will not be affected. Of course if F-Droid no longer exists, that means we lose the largest centralized repository of open source apps which is a huge blow. There are other ways of installing and updating open source apps like Obtainium. But the big thing with F-Droid is that it also provides discoverability.