Why would they wait till 30K miles. It can be done now.
GM is now advertising that they can run diags on your car periodically, as
you drive it (through On-Star), then send you the results via e-mail.
Because On-star is a two way system, they could download new code into your
car, in the middle of the night, without you even knowing it, till the bill
arrived, that is.  They could sell you this upgrade, without you even having
to take the car in for servicing.