> though, you're still probably over at the company, even though they'll diplomatically pretend that you're not

If you're professional about it (be factual, straightforward, and don't do a burn-the-world email blast), I wouldn't assume this to be true. Sometimes companies simply make bad high-level hires and are happy about exposing and terminating them.

Or sometimes not. But the vast majority of CEOs want to know when their direct reports are lying to them and would be happy about this outreach.