The author pointed out that one potential problem is feds subpoenaing data from the AAMVA and not notifying the state of California that it had done so. Given it's such a short article, I can't think of a good reason for why you would have overlooked this.
I didn't overlook it, it's simply not a relevant point. The state won't do anything about a individual subpoena wether it's against the state or a company.