The CEO of a gigantic company, who's most likely already absolutely swamped in email, is asking people to email him at his direct, known-to-public address, which is most likely managed by a team of secretaries, instead of providing a specific target address along with instructions on how to send mail there anonymously.

I don't think anyone would dare take him up on that offer in the first place, and if he's really this deluded about it, he might end up taking zero incoming mails on this topic as "proof" that everything is fine.

That remark about contacting HR is also a little funny, since it seems like employees already consider HR to be enemy agents.