I don’t think you’re using the right reference class for the question. If we’re talking about the set of people who might find Less Wrong interesting, I predict that most of them would find it more weird if two atheists from atheist families got married by a priest than if they got married by the head of an Internet community. (Most normal for that reference class is picking a celebrant who’s just a friend, or a Unitarian minister, or a comedian, etc.)
In a church, with two families present, by a priest. Just because it’s nonsense doesn’t make it not normal.
I don’t think you’re using the right reference class for the question. If we’re talking about the set of people who might find Less Wrong interesting, I predict that most of them would find it more weird if two atheists from atheist families got married by a priest than if they got married by the head of an Internet community. (Most normal for that reference class is picking a celebrant who’s just a friend, or a Unitarian minister, or a comedian, etc.)