If Google "breaks" AOSP, I am pretty sure that the next big thing will be a fork of AOSP. But that would probably be bad for Google (they probably wouldn't want Samsung + Huawei + others to start maintaining a fork of AOSP, I think).
That being said, it's Google. Even you didn't sign anything that says you're not allowed to do Google-less Android, when you launch a non-Google device, Googly devices may just "mysteriously" fall into "oops sorry we are understaffed, we don't have time to handle your requests".