Some cases are more severe than others.  For me, it was minor and resolved itself after about a month.  There are "anti-rattle" clips that help seat the break pads in the caliper.  These metal clips are right up against the caliper (metal) and squeak/chirp during certain impacts on the road surface.
To confirm it for myself, I sprayed WD-40 silicon in the tiny gap between the clip and caliper, and then went for a drive.  Sure enough, the squeak chirp was gone... but as the WD-40 evaporated it came back.  Just was I was going to the dealer for an oil change/tire rotation (free, part of the deal when I bought the truck) and to have the squeak addressed... it went away the day before.  And hasn't been back.
Somewhere on here, a member has a case # for this issue.  I don't think there's a TSB# yet, but I might be wrong, and is worth checking out other posts on this issue.