My assumption is that it is engagement juicing. These seem to go out to seldom/casual users a lot of the time, and people respond by logging in and checking things out. Easy way to pump the MAUs
Which is guaranteed to generate press articles.
a) did this intentionally to improve their KPI numbers
b) did this accidentally-ish but won't roll it back because it's making their team's KPIs look good and is playing dumb