I have switched from winter to summer tires a number or times and at each change of position (rotation) of tires, if the "new" wheels are not "Trained" you will receive a "Tire Presure Sensor Failure" notice on your dash board. I have occasionally had the tire guys tell me "NO NEED" but the warning always comes on if the "trainer" was not used to tell the wheel it is in a new location.
I guess I do not know why the other poster has not had this problem, unless he is replacing his wheels to their former locations.
I would figure the tire sales location would know which sensor to put on, though I purchased my winter wheels sensors over the internet and handed them to my tire changer who did not charge extra to train them. I have also never had to pay extra to have them "trained" on seasonal changes.
I might say my BLIZZAKS are GREAT in snow and in the cold, but are like BUTTER above 50 degrees F, in the rain which is not unheard of on Long Island in winter.