Short answer: No (usually).
In most cases, *AS LONG A YOUR ROTORS ARE WITHIN THEIR WEAR-LIMIT, WHICH SHOULD BE STAMPED ON THE ROTOR*, you can get away with using our brake pads on used rotors.
Often times rotors will wear unevenly over a long period of time (a season or two). This will create a concave & uneven surface which not allow for the proper 100% brake pad surface to brake rotor surface contact.
How do you know? Feel it with your fingers - pinch the rotor and pull away. You can usually feel if there is a worn "dip" (low spot) or high spot.
Another good indicator can be stripes on your brake pads after use (see photo). The stripes here show that the brake pad is only touching the high-spots on the rotor.
Here is a great example of a brake rotor with a low spot right down the center. This rotor is worn and needs to be replaced.