It should be addressed.
It's safe to say that close to 100% of the people celebrating the murder are leftists. Leftists are also the loudest people -- at this moment in history -- in regard to labeling speech as violence, and extending the concept of incitement to include dog whistles.
Ya know... it's the leftists who want Jordan Peterson censored because he might inspire violence against trans people. It's a dumb argument; but, they make it.
Brian Thompson's murderer engraved the words "deny", "depose", and "defend" in the bullet casings that were left at the scene. Those words are strikingly similar to the book title, Delay, Deny, Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About It, by Jay M. Feinman.
It's similar enough that the police are examining connections.
If it should be criminal to say, "Not all Muslims are terrorists, but all terrorists are Muslims." or some other bullshit, because somebody might be "inspired" to commit a crime (as a lot of leftists believe should be the law), then the leftist view should clearly be that Mr. Feinman should be in legal peril for writing his book.
Of course, in this specific case, leftists would see that prosecuting Mr. Feinman, even if the murderer were to directly point to the book as inspiration, would be absurd. But, the law isn't written for individual cases. The legal restrictions on speech, that the left has been demanding for years in regard to "incitement", if enacted, would surely put Mr. Feinman under immediate investigation for inspiring or inciting the murder.
Of course, I'm a free speech absolutist. Since I don't have my head firmly planted in my own ass, I'm capable of putting the culpability of the crime solely on the person (or people) who were directly involved. Even if Mr.Feinman wrote that the health insurance CEOs deserve to die (which he didn't), I would defend his right to say it.
I know that leftists are delusional. Still it's worth pointing out the extent of the delusion. You can't restrict the speech of others, or treat speech as an action, without putting yourself in peril.