Frankly, I don’t know how they are supposed to keep track of 13 vehicles in a giant pool of millions. I’m sure they just use a standard database of purchased-new cars, and not much else. I have a hard time just ensuring my 100-member datalist is all correct and up to date.
It shouldn’t be too hard to determine the VIN numbers of those 13 cars. I’m sure NHTSA has them.
I’m not even sure that legally they would be allowed to take cars off the list. The recall laws likely require that every owner be notified.