If you purchased in the US "the first two service visits are free"
Actually Chevy pays for them to get you established with the dealer, habit of taking it to them for service.
Your assumption is correct, the only service the bolt requires at 7500 miles is the tire rotation. If you prefer to do it yourself you can, the only risk you take is if you ever wish to file a claim for "tire wear" under the tire warranty they can demand proof of proper rotation.
The "required services" are listed in the owners manual on page 311-313, and I think that statement is misleading, as I have the receipt for my first service and the only listed item on the paperwork is "tire rotation"