maybe i'm missing something but i really can't read all that from that quote. suggests to me they are stating the difference, as they are stating it right there.
i think it really depends on the teacher. i suppose i'm just being obvious now. but there's nothing wrong with chicken tikka pizza if you say this bit here is italian, and now i'm adding a bit of indian. the difference is what you do and don't say. maybe there's more info behind the quote than is accessible here. surely fusion is worth doing for as long as someone wants to. but if they label it as something other, that is where it makes a difference.
nevermind, i'm rambling...