It's just that "isomorphism" has a very well-defined meaning, and this is essentially cargo-culting mathematical-sounding language to refer to something that has nothing to do with isomorphism at all (at least, not in the sense that the word is usually meant).

You can do all the reverse etymology you want, but in the end, we all know this is just a word that JavaScript kids are using because it makes them feel cool.

This sort of reminds me of when that weird kid nobody likes tries on a new nickname (like "The Chief" or "Serpent" or "T") and I have to kindly say, “Hey bingo/bud, I'm really sorry, that nickname is just not happening".