Corporations are required to have human directors with full operational authority over the corporation's actions. This allows a court to summon them and compel them to do or not do things in the physical world. There's no reason a corporation can't choose to have an AI operate their accounts, but this won't affect the copyright status, and if the directors try to claim they can't override the AI's control of the accounts they'll find themselves in jail for contempt the first time the corporation faces a lawsuit.