Yes, he clearly knows that, he gave multiple specific examples of local environment and local practices. I agree, terroir is not an elusive and untranslatable concept, it's a well understood and widely translated concept.
It could still be adopted as a learnèd (read: pretentious) borrowing from Greek, of course, but in that case it would be spelled epicharicacy.
[0] Edit: Well, hardly ever. https://en.wiktionary.org/wiki/Citations:epicaricacy#English
IMHO it is indeed untranslatable in the sense that there is no single word in English with the same meaning so that a translation requires a description (illustrated by my quote from Wikipedia that spends a whole paragraph explaining what it means).