That's not quite how things are in practice. At the Cape and Vandenberg they need to submit a scheduling request to the range. In the past, the Air Force wouldn't allow launches within 72 hours of each other. This caused some conflicts as SpaceX (and to a lesser extent ULA and Orbital/Northrop) upped their launch cadence over the last year. In theory with the Falcon's automated FTS they can launch more frequently than that, but I don't think that has actually happened.

Leasing the pad also prevents SpaceX from making certain modifications and puts some infrastructure constraints on them