(Agreeing, with an asterisk.)

Markets care about predictability.

To that end, it's the secret and the reveal of that secret that's the issue for a leader. If a CEO is open about his socially-unacceptable behavior from the beginning, there's no shock to absorb.

Yep that's an even better point. Though I would say there's a distinction between socially-unacceptable and untrustworthy. Being forthcoming both limits surprise (per your point) and mitigates the trust component of deviance.