I'm curious if that is a current petition (even though it's on their website).
I have been doing a lot of research on the relationship between Mormons and Utah Freemasonry. While there was an unofficial ban on their membership from the beginning of our G.L., it did not become official until 1925 and then was not added to the petition until 1927. The ban was removed in 1984 but the petition was not updated until 1986.
Would be curious what the GSec or GM had to say. I don't know either of them or I would reach out.