You love you some semantics doncha?I understand "outing" to be a thing motivated by enmity of some kind, or by irresponsible casualness. I think doing that is wrong (at worst) or careless (at best). A teacher talking in confidence to the parents of a child about matters of concern regarding the child is not "outing." It is showing love. It is caring. I've only ever been speaking of the latter. I have not once advocated for teachers to "out" students about any issue.
Whatever terminology you want to use, should teachers be required by law to inform parents? And if so what kind of enforcement mechanism do you think would be appropriate?