They were the universal teachings of the Church. There have been authoritative non-ecumenical councils in the East and West in the past. For example, the Byzantine Churches had the Hesychast Councils which were authoritative despite not being considered ecumenical.I’m merely playing devil’s advocate here, but if one accepts the decrees (or “doctrines” if one prefers), how can one not consider the council “ecumenical”? IOW, under what authority were those things promulgated? They didn’t just appear out of thin air.