I found this lecture by Fr. John Erickson pretty interesting and wished to share it. He talks pretty openly about teaching on Autocephaly and a future Council.
I'll have to check that out!
Honestly, I think it should be a system that only Autocephalous Patriarchates can grant Autocephaly. But historically, from what I've seen, it is quite vague. Many have unilaterally declared autocephaly or autonomy, which leads to a schism, which is later repaired and autocephaly is granted anyway later. So for them it could be debated whether it came from the unilateral act, or the official recognition.
I know today that many Orthodox Churches, at least here in America, commune Macedonian Orthodox, recognizing that the schism is political and just having to do with autocephaly vs. autonomy.