I don’t know if I would rely on ethics being much of an issue for the tech companies. They allow, and have allowed truly awful things on their platforms. Notwithstanding sex abuse, animal torture, dubious porn, they also had those jihadi videos that Isis et al posted. Many countries around the world carry out capital punishment, publicly too. Some have it in principle, but haven’t used the death penalty for a while. It is only a wet weekend, historically, since European countries abolished the death penalty.
I suppose that once you allow spectators at all to witness the state execution of a person (say town square for gibbit, inside viewing room), is it any different broadcasting it. I am not saying I agree with it, or indeed the execution of somebody by the state. Just that maybe the public spectator issue is already happening anyway. In a more limited way, of course.