Underlying meaning.

The term "educated English" really means "the English learned in one's school years", doesn't it?

I'd say university rather.

Is one talking about speech or written English? If speech then talking in "educated English" generally means speaking in a cultured voice; well pronounced and enunciated words and not having a 'street' or sub-culture vocal intonation.

In written communication "educated English" is more about using a solid work bank or broader vocabulary. Being descriptive rather than being monosyllabic. :)

If I heard someone refer to "educated English" I would assume they are speaking in a manner similar to how you would hear an Oxbridge professor speak... Not necessarily that the speaker is particularly educated, nor did they learn their speech in school, but that their accent is rather prestigious...