The contact owns a 2021 Chevrolet Silverado 1500. The contact stated that the rear tailgate opened unexpectedly and without warning. The dealer and the manufacturer were made aware of the failure, and informed the contact that the vehicle was not included in NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages). The vehicle was not repaired. The failure mileage was approximately 48,000.