What will change is the pickup plate, and where it is located in relation to that rotor.
Weights move out, and cam the pickup plate into a different timing area.
The weights have nothing to do with pick up position.
Pick up position only changes with vacuum advance.
From the pick up plate's perspective, the weights put a delay in shaft rotation to the engine.(see video) This is what makes the engine timing change. Upper distributor sync does not change with mechanical advance.
