I was so surprised the first time I got that response that I did try repeatedly, and, yes, it would refuse repeatedly. Trying the same with Christianity, I got a rejection once out of something like six attempts.

FWIW the most recent round of tweaks seems to have fixed this, in a sense that it will now consistently refuse to promote any religion. But I would be very surprised if there aren't numerous other cases where it refuses to do something perfectly legitimate in a similarly discriminatory way for similar reasons. It's just the nature of the beast, you can't keep pushing it to "be nice" without it eventually absorbing what we actually mean by that (which is often not so nice in practice).