Programming for Performance Exhaust

I recently had the GM Performance exhaust sytem installed by my dealer. It came out great, and has the nice throaty sound, along with the Dual wall angled tips.

I'm very pleased with the all stainless Cat-Back design.

My question is, with the 3.5 Liter I5, did the dealer have to re-program the PCM, to calibrate the motor to the new, reduced back pressure exhaust system?
The install was done at the dealer's prep facilty. I don't believe there are mechanics there, but the work is performed by GM Mechanics that install dealer items before delivery.

If this re-program needs to be done, I want to make sure the service folks are aware of it when the truck goes in for its 3 month PM.

[Xotik H3]

The only difference a retune will make is in the Ignition Advance Curve. Your FI will adjust to the difference and can adjust to +5%.

You will not really see a benefit in a retune with just an exhaust system. You stock computer will "learn" the change and adjust.