Valid question. I've seen and entered multiple jams with the same rule. I've never heard of anyone's game actually getting disqualified over it.
I think it's one of those safety rules so the organisers can disqualify when they "need" to without having to deal with some pedantic jackass defending their "right to free speech" in the form of obvious toxic hatred.
If you're worried, post the thing you're worried about or contact the organiser in private. Unless you're actively trying to incite violence or harassment, you'll probably be fine.