I am now questioning the accuracy of my claim that the use of the vernacular is as characteristic of the Eastern rites as it is of the Novus Ordo in its vast number of translations into modern languages. Yes, in many linguistic spheres the vernacular will be used (as when the Divine Liturgy is offered in English, as throughout the United States), but there are far too many exceptions.

  • Greek speaking churches/patriarchates use liturgical Greek, not vernacular. Some patriarchates use Arabic and others alongside Greek.
  • Slavic Orthodox churches have always used exclusively liturgical Church Slavonic. Recently, Eastern modernists managed to introduce vernacular, but not everywhere. Russians still use only Slavonic. Even though Serbians, Bulgarians, Macedonians, Belarusians, Ukrainians use much vernacular, Slavonic is still in use. 
  • The Romanian Orthodox Church used Church Slavonic/liturgical Greek from 10th to 17th century, when it was replaced by Romanian (which was nevertheless influenced by Church Slavonic, making it quite non-vernacular).
  • The Georgian Orthodox Church uses old literary Georgian as liturgical language.
  • The Coptic Orthodox use literary Coptic language as liturgical language. Even though its use diminished during long Muslim rule (replacing it by Arabic), it’s still alive and it’s being reintroduced.
  • The Ethiopian Orthodox use Ge’ez as liturgical language, not one of many vernaculars.
  • The Syrian Orthodox use classical Syrian and Arabic. Use of Arabic is related to centuries of Muslim rule.
  • The Armenians use a classical literary Armenian.

Moreover, what do we mean by “vernacular”? Old Church Slavonic, for example, was created so that the Slavs could understand the liturgy, but at the same time, it was created to translate a very fancy liturgical Greek. And historically, in most cultures there was by definition a large gap between literary language and spoken language, much larger than is typical today, both because more people today are literate, and because high literary language has basically disappeared.

Source: New Liturgical Movement: The Byzantine Liturgy, the Traditional Latin Mass, and the Novus Ordo — Two Brothers and a Stranger