The way Matt Levine explains it is that something bad happens, but investor communications implies that it doesn’t happen. So, for example, the company has publicly disclosed that it has a policy against sexual harassment, but sexual harassment happened, so having a policy is seen as lying to investors that everything is okay.

So, this isn’t about committing securities fraud, it’s about writing something that shows that the company knows that something bad is going on. It’s about evidence.

Also it is very common and easy for people to speculate wildly about what might be going on, to make jokes, and to use legal terms they don’t really understand. This is Hacker News; you know this. In court, such nonsense may make it look like you actually knew something.