So this canon is not talking about churches separate from Rome, for it speaks of "condemnatory or declaratory sentence" which are no needed for the Eastern Orthodox.
Well, there's those who are excommunicated and those who are excommunicated after a declaratory sentence.
The first are those who espouse public heresy or join condemned sects, the second would be someone like Fr. Feeney who was suspended a divinis
, which I understand to mean that he was barred from administering the sacraments, I do not think he was cut off from the Church.
Eastern schismatics are excommunicated ipso facto, without any sentence. The Greeks deny the procession of the Holy Ghost from the Son, and with the Russians refuse to submit themselves to the Roman Pontiff.