If I understand correctly, the manufacturer has to make an obligation to try to support the third parties, but they are not required to. If they are producing their own parts, I think they have to continue to make them available for five years beyond the time the product is first offered to the public. After that, it gets hazy to me.
I understand that the concern might be over-regulation. I agree that there is some point at which we want to make this reasonable. The idea is that you're going to tell people what your intentions are for the repairability of the product up front.