It's also enough to make news and sound bites. We are talking about mass media here, not a peer review scientific journal.
That doesn't mean it's not also a threat. It just means that if it is a threat they can always say "That's not a "threat". It's a legally-required warning in a regulatory filing for investors of a possible negative event which might occur." Facebook knew journalists would see this and may have wanted it to be reported on.
LOL Impossible to argue with such "logic".
Given that the warning is, as you say yourself, legally required, what do you consider to be the most likely primary reason for it being published? It being legally required (and the consequences of violating that), or "knowing journalists would see this"?
Especially since this wasn't the first report where it was included...