The dealer completed the heated seat retrofit on my 22 Silverado LTD last week. I called in when I saw the GM Authority article. The service writer said he would order the parts for my VIN, and would call me when they came in. He called me with an appointment a week later.
They replaced the trim panel around the HVAC controls. The new panel replaced the dummy switches with functional switches, and included new temp control dials. The service writer also said they re-flashed the BCM. I was in and out in about 2 hrs.