I just do not get Cyprianism!

According to Cyprianism (The Ecclesiology of Metropolitan Cyprian's True Orthodox Church of Greece), the World Orthodox/New Calendarist Orthodox Churches are heretical, but still have grace in their mysteries. How can this be so if the fathers of the Church said that a heretic is cut of from both the truth and the grace of the Church? It seems to me that Russian Orthodox Church Outside of Russia/Russian Orthodox Church Abroad no longer teach that the World Orthodox/New Calendarist Orthodox groups are heretical. Did the ROCOR/ROCA perhaps agree with Cyprianism when they first chose to come in to communion with the Cyprian True Orthodox Church and have since changed?