I believe this recall is being used for nefarious firmware/software updates that are too big for OTA/ONSTAR transfers. Likely updates to their "remote control" abilities that the govt made mandatory as a term of the GM bailout years ago..
I called a dealership and told them they could update/repair any physical hardware they wanted, but they could not hook up any electronics at all and that I would be there the entire time. They replied that GM has added software updates to this recall and they must be done or nothing can be done.
We know one thing for sure, and that is that no corporation or govt entity cares about our safety. they are hounding me regarding this recall as if they do care, leaning heavily toward nefarious purposes.
I work in IT and know that 75% of Microsoft operating system updates are related to their back door access and I am sure that this industry is the similar, particularly after the govt had their evil paws in it temporarily.