https://www.cnet.com/news/some-of-mark-zuckerbergs-old-facebook-posts-have-disappeared/

"A few years ago some of Mark's posts were mistakenly deleted due to technical errors. The work required to restore them would have been extensive and not guaranteed to be successful so we didn't do it," a Facebook spokesperson said in a statement. 

The spokesperson said many of Zuckerberg's old posts about Facebook can still be found on the company's blog and in its newsroom.