I can't yell in a library, the librarians aren't authoritarian. I know going in that libraries aren't the place for that.
Obvious and simple solution here:
1. Allow people to say whatever offensive jokes they want.
2. Keep banning the actual problem: those who make the targeted threats.
The entire concept of "incitement" is ridiculous. We have agency. Nobody can force me to go threaten someone. Go after the ones who commit actual harm, not the ones who make jokes.
Looking at what the families of Sandy hook victims suffered at the hands of mentally ill viewers of Alex Jones is heartbreaking. When you have an audience of millions, I believe you have a responsibility to be intentional about what you publish, because you know that someone might take you very seriously and do awful things.
Sure, we can catch the people who make threats often enough, but the damage has already been done. It's far better to ask folks to be considerate and intentional about who they target, rather than try and sweep up the wreckage of someone's life after the fact.
Reach and influence are important, because they impact the magnitude of what a derisive comment can do to a target.
You saying, "lol, man!" In your living room has no reach, it won't cause harm. The Bee saying it has huge reach, and when aimed at a specific minority individual can lead to serious harm.