If his church is non Chalcedonian, as it appears, he wouldn’t be Orthodox.
Bishop Mar Mari Emmanual founded his own independent church, in a Sydney suburb, in the Syriac tradition. He was expelled from The Ancient Church of the East a few years back, over obscure liturgical quarrels, and mention was made of the Council of Nicaea - which (as you would be aware) is a sign that a debate is getting profound. I have heard that the real reason for these divisions was an ethnic rivalry between Chaldeans and Christian Arabs. The division has largely been patched up now. The ability of the Eastern churches to set up autonomous faith communities is sometimes very helpful to them - they can avoid larger storms - just go off and do their own thing.
Bishop Mar Mari has lots of controversial opinions, being anti-vax, and - even more shocking to the media - preaches against the trans cult. He is firm in his opinions, but warm hearted, and witnesses Christian love. After the attack, he asked for people to pray for his assailant, and refrain from any sort of revenge.