If you want to be a theatre teacher you need an MFA. Easy enough if it weren't for the fact that you do not need it in theatre pedagogy like the logic would want it to be, but in performance.
And if you want to be a working actor you also need an MFA in performance. Which means that getting into an MFA program is a near to impossible thing to do.
So the question is: should you tell the audition committee that you want to be a teacher, hoping that it would set you apart from all the other candidates? Or would you be better off not mentioning it?
The answer is, do not EVER say that your goal is to teach.
Tell the school that you want to be an actor, but never say that you want to be a teacher maybe, now, some day or eventually.
Sure, you need an MFA to become a teacher, but MFA programs want people that want a performing career.
Not to tell is the answer if you need to get into an MFA program.