OEMs are usually pretty committed to maintaining a stock of replacement parts.
See the NHTSA guidance below. It's probably cheaper to maintain a stock of parts for 10 years at predicted consumption rates than to buy back used cars that can't be resold. Service parts is a decent business. And exterior parts like bumpers that are commonly damaged are needed for safe operation of the car. Finally, manufacturers want to earn brand loyalty. Screwing over former customers of luxury cars is inadvisable.
https://www.nhtsa.gov/interpretations/timereplcepartpollak12-03
"Also, under 49 U.S.C. 30120, if either a manufacturer or this agency decides, within 10 years of the date of sale of the vehicle to the first purchaser, that a motor vehicle contains a safety-related defect or fails to comply with a Federal motor vehicle safety standard, the manufacturer is required to provide a free remedy for the safety-related defect or noncompliance. These remedies may include the repair, replacement or repurchase of the affected vehicles."