I think it probably rejects your hypothesis.

I use it frequently with multiple managers and directors. It entirely depends on your relationship with the person. Sometimes you can cultivate a relationship where being so formal and subservient is unnecessary, if not counter productive.

Edit: Not in California, or the US.

I am in California, so perhaps this is just confirmation of your guess that it's a California-ism, but I certainly use "Hey $name" and even less formal things (if that's possible) to address my manager (and even my CEO). I did the same when working in upstate NY, though (~15 years ago), and my impression is that such informality isn't particularly unique.

I've actually never worked anywhere such formality was expected, and suggesting something like that would probably get you some weird looks. I wonder if it's an industry thing? Perhaps some industries tend to enforce politeness/formality between rungs in the career ladder more than others?

I generally use "Great Man, Who Descended From Heaven".