I called GM since the dealer said it was normal, I complained and complained until the dealer finally treated the pads at their cost. They wanted to charge me $85 bucks. Then they did it and said they found a tsb or something and that GM would pay for it. It fixed the squealing for about 2 weeks and now it is coming back. I knew that wouldn't fix it. I am going to keep taking it back until they fix it or buy back the truck. Either way I am not going to let this slide.
When you get new pads, bed them in and it should prevent the squeal.
Here's a link I posted from the Stop-Tech website
I did this on my Yukon and they are nice and quiet.