Let's put it this way.
If the OP is an employee, then yes, the employer can legally require that he attend morning meetings. Even if he is OT exempt, there is nothing in the law that says the employer cannot control his time. Nothing in the law says that OT exempt employees get to set their own hours. It may be unwise if this is cutting him off from potential contacts. It may be poor management. But it is legal.
If the OP is an IC, there there is nothing inherently illegal about requiring him to to attend morning meetings, with the same qualification. It might or it might not serve as evidence that he is mis-classified. But there is nothing in the law that says IC's can't be required to attend meetings, either.