This claim seems to be made by former members of HOCNA who still hold to some version of the "Boston ecclesiology" of Fr. Panteleimon Metropoulos which states that the Church of Greece and Patriarchate of Constantinople only fell from grace in 1965 due to the lifting of the anathemas and not in 1924 with the calendar change. How convenient for HOCNA given that they only left GOARCH in 1965 due to the fact that Fr. Panteleimon was being investigated for sexual abuse.
Elder Joseph the Cave-Dweller clearly DID leave Metropolitan Chrysostom of Florina's synod in 1950 after he issued his encyclical declaring the New Calendarist State Church as graceless. He resumed commemorating the Patriarch of Constantinople shortly afterward.