He's a schismatic of schismatic schismatics.
The Assyrian Church of the East, from my understanding, is the continuation of that same Local Church which schismed away following the Council of Ephesus which rebuked Nestorianism. The then-Church of the East I believe was based in modern day Iraq and Iran. That said, the political realities at the time can not be ignored: the Sassanian Empire, which was the last pre-Islamic Persian empire, didn't quite get along with the Byzantines and so it is highly likely that the Sassanian Emperor at the time may have used Nestorianism as an excuse to distance his people from the Byzantines. At one point the Church of the East reached covered the modern day -stan countries and parts of China until Tamerlane killed everyone in his path.
The Ancient Church of the East went into schism from the Assyrian Church of the East sometime in the 1960s over the decision to switch to the Gregorian Calendar (yes, Gregorian and not our Revised Julian) from the Old Julian Calendar.
Mari Emanuel was a part of this entity but went into schism himself forming his own "Church." This happened after the Ancient Church's patriarch suspended him for a variety of things that ultimately amounts to clerical disobedience. He's also been accused of sexually assaulting a woman right before his suspension, though I'm not sure if that's officially related to the suspension.
So far as I know, no Eastern Orthodox jurisdiction has made formal position on Mari Emmanuel and I don't suspect they would because he's a schismatic from a schismatic church that itself is schismatic of a heretical church. His "Church" consists of a one-parish operation and quite frankly I see little different between his cult of personality and that of any Evangelical personality-driven entity like Joel Osteen or whomever. I would not be surprised of the Australian-based Eastern Orthodox bishops have had to issue some local guidance to their clergy and congregations.
Personally, I wish that the Assyrian and Ancient Churches would reunite for the good of their own dwindling Assyrian communities then for the Chaldean Catholic Church to leave Rome for the Assyrian Church for the same reason (that and being part of Rome just doesn't bring any advantages these days). I'd love for the Assyrians to come to Eastern Orthodoxy and be able to preserve their own liturgical rites and so forth, but that is far above my paygrade.
