This looks like a grand way to get included in a defamation lawsuit, to be honest. Since Facebook is tacitly approving of such messages in their own FAQ, they could become liable.Subjectively described as a criminal, then it's okay to broadcast advocacy for violence against them.
Here's a scary scenario - Some college kid gets accused of rape by a jilted lover, which is vastly more common than feminists would have us believe, under the Title IX Kangaroo System. She proceeds to FB and smears him, and because it's an allegation of criminal behaviour (which is different than a criminal allegation, AFAIK), anyone that threatens violence against the guy is 100% scot-free, because he's been described as having committed a crime, and the veracity of that claim is immaterial.
They just keep pushing that section 230 immunity. God damn. I detest government interference with private businesses but FB is practically begging to get fucked at this point.