I have seen a lot of “Glamour Don’ts” in my time though rarely at WDW.
That being said I’ve an expression that both my children and DGD know: “Don’t bring that home”.
Fortunately, for all concerned, nobody has to date.
It doesn't bother me. But it also doesn't bother me that it bothers you.
Ideally, personally, everyone would be dressed appropriately, but I'm not sure WDW wants to touch that.
It's a struggle to find shorts that are more that 2-3 inches in length and tank tops that don't have neck lines that are extremely low. I'm talking about for my teen daughter