The only time you have to report your position is when you have an instruction to do it. You might for example get "cleared for the ILS runway 14, report the outer marker". In many larger towers they will have a radar display, so they can see you coming whether or not you report. An airport this size will have an agreement between the approach control and the tower as to how arrivals will be presented for the tower to pick up, and in the case you cited, the agreement is to present them at NOAHA and have them contact tower then. The arrival will have already been coordinated between the approach controller and the tower controller so the tower controller is expecting the contact. So you're correct that without being required to do so, it is a matter of preference, and it does no harm to have the position confirmed to the tower controller.