I discovered that the Canvas documentation here says "The Discussion icon  automatically appears as a contact method for Admins so users can contact them through Canvas Conversations. It cannot be selected by any other users."
Does anyone know why the Discussion icon is only limited to Admins? It seems to me that it would be useful for professors and students within a course, since you can contact those people through the Inbox anyway. This would just simplify things.
This has been a significant challenge for our students to adapt to coming from Populi, our SIS/LMS which let us show the email addresses for faculty & students if they permitted it.