My car was at the dealership service center for an entire week. During this time they were in contact with GM while attempting to resolve the issue. The following tasks were performed:
1) update computer software
2) replace HVAC controller module/unit
3) replace climate control / radio faceplate
None of these were able to solve the problem. GM feels this may be a design feature. They are doing additional research to determine if the software is designed to make the a/c come on automatically the first time the fan is used after starting the car, but then not come on again automatically for several hours. I hope that regardless of what they determine, they should at least offer a voluntary computer update to disable this feature. I will provide an update here when/if I learn anything more.