You need to relax. Yes his comment is speculation, does that mean he is necessarily wrong? He is giving his first-thought analysis of what might be the problem at Signal. Is that such a crime?
I don't though think that Musk had that information when he made his off the cuff pronouncement. I think he just says whatever he feels like and everyone automatically assumes he is correct because of his success/riches. This is my main objection to him. Respecting someones opinion and assuming they are correct because they are rich is just plain disgusting. Society should be better than this.
I also think that someone in his position should not be mocking a company that provides a free service. It just makes him look like an ass imo. In turn it makes me think that those who upvote that shit here on Hacker News are sheep.
If he gave some reasonable explanation or details, then fine. If he used reasonable capacity planning and some sort of evidence to demonstrate that such an accusation is reasonable, fine. He didn't.
This is what happened: Musk thinks to himself "Signal is better than Whatsapp, I should recommend Signal and people will think I'm awesome." His recommendation of Signal was merely the statement of an attention whore. Signal was obviously better for so long. Anyone worth anything in security / tech knew this a long time ago.
After Musk recommended Signal, it blew up in his face because they couldn't handle the capacity increase immediately due to his recommendation. This makes Musk look bad, because he just recommended them. So what does Musk do? Musk denounces and mocks Signal.
This is why Musk is an asshole and deserves to be mocked and attacked. It is all a fucking publicity stunt to him. He doesn't give a shit about security or helping out Signal. All he cares about is acting like king of the world. Fuck him.
However, whatever his motivation, I think the guy is genuinely intelligent. It's tough to not admit this. His mere intuition is fair match for the experience of many seasoned engineers (if what we read about him is true). Correct me if I'm wrong, but I do think he donated to the Signal foundation. At the very least he has put money where his mouth is.