I bought my 2015 1500 with 26k miles and now have 50k. I have always noticed a little squeak coming from the back. Nothing noticeable just when pulling into and out of the driveway.
Anyway, my wife calls me and says the truck is making a noise. So I meet her outside as she pulls in. I take it for a ride and it sounds like pads are worn and the indicator is squealing. But the noise is kind of intermittent and changes in intensity whether I’m stepping on the brakes or not.
So I pull the rear driver side wheel and take the caliper off. I remove the Pads and they and rotors look ok. But on the removable clips that hold the pad in place (top and bottom), there is a piece on the inside that is touching the rotor. It seems to maybe act as a spring clip for the pad. I bend it back a little and spray brake cleaner. Put it back together and test drive with no squeaking.
Just my experience. Something like this