basenote it was already stated that this change won't affect GrapheneOS, because it only concern "official" Android builds - basically everything that comes preinstalled stock on Android phones nowadays.
However, this will massively hinder 3rd parties from distributing apps like ReVanced or Nintendo system emulators, since the devs most certainly won't like the idea to disclose their identity to Google, to later get sued by those companies, when Google gets subpoena'd. Similarly, many FOSS devs likely won't reveal their identity either and just stop development altogether.