But this is protected in this case.
I can unfriend you on Facebook for saying “I’m not sad he’s dead”. (And to be clear, Kimmel didn’t even go that far.) I can kick you out of my birthday party. I can complain to your employer. They can fire you. (They can fire you for having tattoos, or red hair!)
But the government cannot do these things. That is the entire point of the First Amendment. The FCC can not threaten the license of a broadcaster for protected speech, but we are here anyways.