You are under no obligation at all. Some S. Korean schools are privately run and owned and their administrators have a different view of what teacher’s rights are. Principal Perry Kalynuk should never have shared your email without your permission. That’s just good manners in most places and good law in others. Also, since you were dismissed with little notice, it is surprising they would want help from you.
You are dealing with an unprofessional school. Bush league. Move on.