Nobody is communicating anything valuable over Twitter. This is such a ridiculous point that people bring up all the time. Scandalous relationships? Most of that will be on true messenger applications. Business deals? Business email. Many more mainstream prominent people don't even run their own account.
It's not that everyone is so security-minded, it's just that Twitter is an extremely inconvenient way to maintain personal relationships.
> I think the Bitcoin scam was also the perfect innocuous cover story
There is almost no value in DMs. Funny seeing HN speculate about these elite hackers selling them as if there's any market for them, let alone one that would pay $100k+.