They officially named Coach Taylor head coach of the women's cross country team, and at the bottom of the press release they say she "is of Indian decent and grew up in the Sikh religion. Taylor is not a member of the LDS Church, which sponsors BYU. While in the past head coaches throughout BYU athletics have often been members of the church, it has been a practice but not a policy."
So the head football coach does officially not need to be a member of the church.
Sorry if already posted