Isa- Let's cut through the tangents which you seem very fond of.
We have a modern English liturgy now, so your point about diglossia is moot.
We have WRO now, so your point about uniformity of rite is moot.
No one is fighting to adopt Middle or Old English.
But they are fighting to adopt WRO: what became the "Nordic Catholic Church" went over to the Polish National Catholic only after the Greek bishop of Sweden stated that he didn't want the idea to get out that Orthodoxy was for Scandinavians.
As an aside, Elizabethan English is in fact our closest parallel to, say, Classical Chinese or Attic Greek, because it is generally recognized that English literature and English expressive power reached its highest point in that era (Shakespeare, KJV, Milton, Spenser, etc.), Beowulf, Sir Gawain, and Chaucer notwithstanding. Old and Middle English are often said to be less flexible and less rich in expressive power and subtlety than Early Modern English.
That's about the only thing it has in common with a parallel with Classical Chinese, Arabic or Greek. Nowhere near the difference between it and formal English of today, because both are Modern English. There are other problems with the comparison, but I wouldn't want to go out on a tangent....
Bishop Kallistos, however, made a statement which makes it moot anyway: he stated that he translated the Festal Menaion and Lenten Triodion (which are in the language you speak of) because he was raied with that style (KJV and BCP and all being Authorized) and would remain with it to his dying day, but he realized that that was not the language of the Cypriot immigrants (the bulk of the Greeks in Britain it seems) and so modern translations should be done. Such a statement is incomprehensibile in the East (as the Evanglika and other incidents/statements have shown).
That's why poets continued to write in this language up to the 19th century (and some, even today), even after Early Modern English had been replaced by contemporary English in everyday speech. If there is anything to be called "Classical English" it is Early Modern English, not Old English or Middle English.
Someone who argues that every ethnicity or culture should have its own rite has no right to criticize those who think every ethnicity or culture should have its own church.
And to whom are you refering?