Private organization bylaws must pass the anti-trust (if they are a monopoly and adjudged to be one) sniff test.
For instance, Standard oil could not have "bylaws" for the private truck drivers that they could neither pick up, nor deliver petroleum products to another entity in the petroleum supply chain. And, in fact, that's what broke up Standard oil.
You are now going into management vs labor issues.
Sterling is part of “management” and therefore this is not an issue where you end up with management vs labor.
The rest of management is saying “we don’t want you here” which is perfectly legal under the rules Sterling agreed to.
If he didn’t like those rules he didn’t have to sign the agreement