Not in Musk’s defense, I guess there are enough signs that his posture is authoritarian and therefore bound to end up with yes-men, but people in power also sometimes are willing to listen in the proper context. I.e. as long as it is in private or in a trusted forum, where being the Cassandra does not link the warning with their leadership. Of course the really powerful will also react to potentially uncomfortable feedback in a proper forum or in person, rather than in public.
Not those who just punish anyone who dares. Then they're just not told anything but "yes, sir" until disaster strikes.