alt Hacker NewsIt’s compelled speech. A transmission of expression required by law. The argument settled in 1791. The First Amendment does not permit the government to compel a person’s speech just because the government believes the expression thereof furthers that person’s interests.
It's also a consumer product regulation, of which many already exist. The government compels you to speak about the ingredients in a food product you manufacture, and we don't seem to have a problem with that.