No, I'm afraid someone's attractiveness doesn't take them out of the set of people whom it is immoral to emotionally abuse.

We are not obliged, in our personal interactions, to refrain from actions which cause other people any amount of harm whatsoever.

This being so, there must be a point where an action is bad if it causes a certain amount of harm, but okay if it causes slightly less harm.

That being so, "less harm because they are more attractive and can find partners more easily" can be one cause of the slightly less harm.