That’s a good question, and I have no idea. It very well could be a local church-by-chruch basis as the local congregation makes the decision on who to hire by a simple majority vote.
As a example, one near me was looking for a new minister and basically said all are welcome to apply, however we will only pick a openly gay one.
That makes perfectly good sense in Bizarro World. It wasn’t that long ago that Protestant congregations thought it desirable that their pastor (a man) be married (to a woman.)