The background here is that WhatsApp previously stated that they would never share user data for profit, i.e., not selling ads [1]. Reading that blog post leaves a sour taste in HN's collective mouth, because not 2 years later they would get acquired by the ad giant Facebook and now mandate that users agree to share their data with FB. The wording made it seem like accounts that didn't agree with the new policies would get terminated on February 8th.
A few days later, WhatsApp posted [2] that their update was misinterpreted by users and media, and that the clarifications to their policies were to increase transparency. They also pushed the ultimatum for a few months.