Dee Sandgren, Clyde's son, was my bishop when I was at BYU. I even
got some old sheet music of the fight song one time when Dee was
cleaning out the old family attic. I asked him one time about the
changes, and he told me that the administration came to him asking
him if it was OK to change the lyrics because a women's group was
putting pressure on them to have it changed (I don't know if there
was a lawsuit or if they were threatening one). At first Dee was
very adamant about it, but after awhile (I believe he said after
praying about it), he realized it didn't matter and it would be OK
to change it. So they did. But I still sing 'Stalwart men and
true,' and I'm a woman.
By the way, I can't find where I put that sheet music (in a box
somewhere), but I don't remember it having the lyrics 'Rise all men
in blue' and I believe it was the original sheet music.