faith on your mission to whom you wanted to teach the restored gospel. But they had made a "commitment" to be a faithful Catholic all of their life. Would you expect them to honor that "commitment"? So reneging on a "commitment" is not necessarily dishonorable in certain contexts.
I expect you would argue that if they went to a Catholic school the Catholic school should have the right to expel them. I am not arguing whether they have the right to, I just think it is a terrible idea. We should embrace people who have the courage to follow their conscience in matters of faith, right or wrong, rather than people feeling they have to keep it hidden to avoid expulsion.
I don't think we do anybody any service by expelling people for following their conscience in matters of faith. I don't think the "there are faithful Latter-day Saints waiting to get into BYU" argument is very persuasive.