2018 BMW 640I Power Train Problems

I took my vehicle for a regular oil change and vehicle check at 22000 miles. The service advisor performed a routine check and found that the driveshaft flex disc had multiple cracks. If the cracks expand, it could lead to a complete failure of the disc at which point the driveshaft was come loose and can cause an accident along with extensive underbody damage. I do not understand how a certified preowned vehicle with only 22000 miles can have such a major part defect.