Enables you to post something with an expiration date and time.
Many users of FB do this now but manually: they post a topic, and when challenged on the accuracy of the topic or post, they delete it.
This enables the spread of inaccurate views intended to influence others while simultaneously avoiding challenges. In the field of propaganda, the first message that consumers receive is the one most likely to stick, even when it is wrong. Propagandists know that most people share before thinking, thereby using social media as a frictionless conduit for propaganda.
Past posts about the use of social media for propaganda purposes are here.