Perhaps a shot in the dark here, but I’m guessing the author is working from the premise that Orthodoxy is already in many pieces. While oversimplifying, the truth is that the Orthodox Church consists of many jurisdictions which are not in communion with each other. Kolokotronis, you cannot say one leaves Orthodoxy in the same way a Roman Catholic can say one leaves Catholicism. Orthodoxy has no single See, but a conciliar system which, again, is in many pieces. Out of communion yes, but out of claimed Orthodoxy no.
The call here seems to be to recognize the history of the fraction tearing at the whole. The devil does not fight over conquered ground.
This isn’t true. The Orthodox Church by definition includes the various hierarchies that are in communion with each other. That’s what it means to be an Orthodox church. As to “claimed Orthodoxy,” why, you can claim to be a duck, too. That doesn’t make you one.