Which ones? I'm pretty sure that being "Android" means that you are certified by Google. You cannot sell an Android device if it's not certified by Google.
> It's become sort of a GNU/Linux kind of distinction where the "certified" Android is AOSP + Google
It depends on the context. If someone asks you "are you using Windows or Linux?", answering "I'm using GNU/Linux" is a way to show that you are that kind of people. But if someone asks you what userland you are using, then suddenly it makes sense to make a distinction between GNU and, say, busybox.
When someone asks me if I have and iPhone or Android, I say Android (even though I am running GrapheneOS). But when we're talking specifically about an alternative to Android that builds upon AOSP, then I think it makes sense to make a distinction. There is a whole (niche) market of AOSP-based alternatives to Android, that users choose specifically because they are not Android. When we talk about that, it makes sense to use the right words.