As long as they don't disobey laws regarding parking, noise levels, commerce, etc, they should be protected by our constitutional rights in this area.
I am an atheist, and I would HATE being the neighbors who had to put up with this. But, I am also a supporter of rights of the people. What if this was applied to the boy-scouts, tupperware parties, garage sales, backyard picnics, family reunions? Nope. The municipality that is seeking to do this is way off base, and I hope the California Supreme Court gets the case in time and pitches it into the Pacific.
Jeff