As the members of the governing body change so do the rules. No god involved just the opinions of the men in charge.
I think it might also be that they like to throw the rank-and-file a bone now and then to try to keep them happy and feeling grateful. Give them back something that they shouldn't have taken away in the first place like they did with beards. Never admit you were wrong but present the change as new light that came about through prayerful consideration.