Amusing. A Catholic professor trying to instruct the Orthodox world on how a pan-Orthodox Council should work, and how it should include Catholic concerns. If the Catholics want to be part of such a council, their church should recant its schismatic doctrines and rejoin Orthodoxy. Otherwise they can be spectators like the rest of the non-Orthodox world. All are invited to become Orthodox, but none may dictate what Orthodoxy is from the outside.
Alternatively, the Orthodox could be polite and allow Catholics to attend, as the Catholic Church has allowed Orthodox to attend councils...Or even better, the Orthodox could join the Uniate Churches in rejoining the Universal Church (however you want to cut it, either a gradual drift or an Orthodox departure, the Catholic Church was never a part of the Orthodox Church, and thus never "left Orthodoxy").