Earlier quoted context omitted.
It was intentionally "leaked"; the whole thing is a PR move. Facebook's entire business is predicated upon having intimate knowledge of its users and is as such irreconcilable with the concept of privacy.
Why is this downvoted? Zuck decried leaks for years when "leak it to the press" became the only way for rank-and-file employees to affect change on contentious topics, particularly in the wake of Cambridge Analytica. Anything sent to employees these days is 100% expected to be repeated in the press and would be written with that in mind.
HN is predominantly ad-tech or ad-tech related people. It's uncomfortable for them.