It isn't used in English in any context other than writing published in the New Yorker... except for the word "naive" (and "naif"), where it is still sometimes used. The criticism of the New Yorker is well founded.
It’s in use. It hasn’t disappeared. It’s not the norm, but it is definitely still in use.
It was hard for me to type those on my English keyboard. That's reason enough for me to say they are not really part of English any more and haven't been for decades. I do like writing connexion sometimes, and I note that this isn't even considered a spelling error in my installed dictionary, unlike coördinate, but I'm not going to claim that it's "still in use" because I read a dictionary one time.
It’s not “still in use” because it’s in the dictionary.
It’s “still in use” because it’s still in use.