Exactly what canons would be violated by such a move?
Canon VI First Ecumenical Council: Let the ancient customs in Egypt, Libya and Pentapolis prevail, that the Bishop of Alexandria have jurisdiction in all these, since the like is customary for the Bishop of Rome also. Likewise in Antioch and the other provinces, let the Churches retain their privileges. And this is to be universally understood, that if any one be made bishop without the consent of the Metropolitan, the great Synod has declared that such a man ought not to be a bishop…
Canon II Second Ecumenical Council: The bishops are not to go beyond their dioceses to churches lying outside of their bounds, nor bring confusion on the churches; but let the Bishop of Alexandria, according to the canons, alone administer the affairs of Egypt; and let the bishops of the East manage the East alone, the privileges of the Church in Antioch, which are mentioned in the canons of Nice, being preserved; and let the bishops of the Asian Diocese administer the Asian affairs only; and the Pontic bishops only Pontic matters; and the Thracian bishops only Thracian affairs. And let not bishops go beyond their dioceses for ordination or any other ecclesiastical ministrations, unless they be invited. And the aforesaid canon concerning dioceses being observed, it is evident that the synod of every province will administer the affairs of that particular province as was decreed at Nice. But the Churches of God in heathen nations must be governed according to the custom which has prevailed from the times of the Fathers.
Canon XXVIII Fourth Ecumenical Council: Following in all things the decisions of the holy Fathers, and acknowledging the canon, which has been just read, of the One Hundred and Fifty Bishops beloved-of-God (who assembled in the imperial city of Constantinople, which is New Rome, in the time of the Emperor Theodosius of happy memory), we also do enact and decree the same things concerning the privileges of the most holy Church of Constantinople, which is New Rome. For the Fathers rightly granted privileges to the throne of old Rome, because it was the royal city. And the One Hundred and Fifty most religious Bishops, actuated by the same consideration, gave equal privileges (ἴσα πρεσβεῖα) to the most holy throne of New Rome, justly judging that the city which is honoured with the Sovereignty and the Senate, and enjoys equal privileges with the old imperial Rome, should in ecclesiastical matters also be magnified as she is, and rank next after her; so that, in the Pontic, the Asian, and the Thracian dioceses, the metropolitans only and such bishops also of the Dioceses aforesaid as are among the barbarians, should be ordained by the aforesaid most holy throne of the most holy Church of Constantinople; every metropolitan of the aforesaid dioceses, together with the bishops of his province, ordaining his own provincial bishops, as has been declared by the divine canons; but that, as has been above said, the metropolitans of the aforesaid Dioceses should be ordained by the archbishop of Constantinople, after the proper elections have been held according to custom and have been reported to him.