Earlier quoted context omitted.
They signed a waiver that mentioned the risk of "death" 3 times on the first page. I'd call that broadcasting. Edit: I mean just read the waiver: https://nypost.com/2023/06/23/read-the-death-waiver-doomed-t... It speaks for itself.
I think this is only partially true. Generally, Risk = probability x severity. From that link, they characterized the severity (death) but not the probability. Saying "you may die" is different from saying "your have a 50% chance of dying." My guess is nobody had a good estimate for the probability so nobody could have accurately communicated the risk.
I don't know. This implies a high probability to me.