If these two exchanges integrate LN then it would help everyone and also promote Bitcoin LN. As we all have an account on either of these two big exchanges.
But it's not in their interest to improve the bitcoin ecosystem. Let users find their own innovation, if it "benes" enough for us, then we will start facilitating them.
Cz is a businessman who perfectly reads market potential. If you see today that there are still countless LN bitcoin users, I think binance has no reason to expand too quickly on new support features that don't add much significant profit.