It is the teaching not just of how to do something, but why we do it, and how others react to what we do. It is the learning of cultural norms, such as, when you enter college, your parents no longer are able to speak for you, and you must be prepared to advocate for yourself, and then teaching the most effective way to do that.
Not to mention, learning to self-advocate is especially important for deaf students and people with any disability that makes it harder for them to enter the workforce cause of other people's attitudes. Since deafness and disabilities in general often lead to having to constantly prove oneself, having strong self-advocacy skills are essential.