It's likely not legal. But there are many bigger questions, including:
Does this nonsense ever pop up in any other specialty? Med students take note, if you haven't already.
Why does this stupid person feel empowered to dream this up?
What are you (and your colleagues) doing or not doing that allows this stupid person to believe they can do this to you?
When do you plan to tell this stupid person their stupid idea is stupid?
Do you feel deserving of respect? Personally? Professionally?
On the other hand, I do feel people deserve what they get. Because they generally agreed to it or are complicit with their situation. If one's primary concern is collecting a biweekly paycheck and not having to deal with the practice of medicine (including practice management, billing, independence, etc.), then being treated as a run of the mill employee (e.g., replaceable, nonessential, told how to work) is part of the package.