Facebook chats sent by Zuckerberg from several years ago or older were missing from the inboxes of both former employees and non-employees. What’s left makes it look the recipients were talking to themselves, as only their side of back-and-forth conversations with Zuckerberg still appear. Three sources asked to remain anonymous out of fear of angering Zuckerberg or burning bridges with the company.
[Update: Recent messages from Zuckerberg remain in users’ inboxes. Old messages from before 2014 still appear to some users, indicating the retraction did not apply to all chats the CEO sent. But more sources have come forward since publication, saying theirs disappeared as well.]
https://techcrunch.com/2018/04/05/zuckerberg-deleted-messages/ [techcrunch.com]