It has to do with religion by nature because the activity being done is a religious activity. Which is protected by the 1st Amendment. So, if you restrict it in any way, regardless of if you intend it or not, there is a question of the First Amendment Right of the free exercise of your religion. Now, based on the case law posted by JE, SCOTUS has held that this type of restriction would not violate the First Amendment Right to free exercise of religion. But, that does not mean that the right to freedom of assembly, also guaranteed by the First Amendment is nto also implicated. In the end, I think that too would be found not to be violated because the proper "due process" is being done in investigations and hearings. However, to say there is no Constitutional issue here is patently false, it turns out that I think that Constitutional rights are not being violated, although I could argue it the other way, but just because the end conclusion is that rights are not being violated does not mean that there are not Constitutional, in this instance freedom of religion and freedom of assembly involved. This really should not be that difficult for people to understand.