He always seemed to me to be a guy of basic integrity. Not a guy who would stab someone in the back. Open about his past drug abuse, stood up for guys like Chris Farley who he said the studios basically killed, was able to maintain friendship with some of his SNL castmates like Sandler etc.
If he knew about her condition, it was a disrespectful comment to make and I wouldn't have been surprised if Will had a firm chat with him after. As it were, it's comedy, and noone is safe if you want to be in the crowd with the cult members. I think Will, like some others such as De Niro, started to believe the people he played on screen is who he is (Ali).
Violence is rarely an answer. Rock probably knows he deserved some response, though not that. I may rejoin Netflix for a month just to watch this. I've always found Chris to be genuine and certainly funny in films (Lethal Weapon IV was his best IMO), not too sure I will be into his stand up, but he seems a decent enough guy to receive some support.