Taboo words should be taught. You should know what people are saying to you.
I remember when I first came to America. I was trying to practice English at the mall. The sales woman did not like me and she called me a "stupid foreign ----." (I remember the last word she said but I don't want to type it

).
I was not sure she was making an insult. I knew "stupid" could be bad, but I wasn't sure.
But I knew she was insuling me because of my friend. He was very upset and he made us leave the store.
The lady was smiling. She talked like she was being nice but used the bad words. If I was alone I would not have been sure about the insult. If I had known the bad words, I would have been sure.
This is why I think teachers should teach taboo words. It is important to know what people are saying to you. We cannot know that for certain if we don't know the words they are using.