From what I know of the law, I actually agree with former U.S. attorney general Michael Mukasey that it is an unconstitutional limit on the chief executive’s legitimate military powers. However, President Obama did sign it into law.
Not even close. A military detention facility is in place and run under the UCMJ. The military has congressional authority to discipline itself and that includes those in captivity. The CIC has the authority to command the forces as in he has the final say as to purpose and mission of the military, not how we discipline ourselves or those whom we take prisoner.
Political prisoners are another story since they are held at the convenience of the CIC, such as Noriega. But POWs and captives are held for military reasons, outside of the scope of the CIC.
But the law does not prevent the exercise of CIC powers - it does not prohibit the release; it is a notification requirement. Could it not be equally Constitutionally valid that Congress, in exercising its Constitutional oversight responsibilities, requires sufficient notification to perform that Constitutional function? There is a balance of powers and the Commander In Chief does not exempt the President from that balance. He is not supposed to be a military dictator.