I've scoured the net looking at this kind of stuff. Honestly, my last vehicle had just a very faint whine on deceleration. Other than that, nothing like it was eating itself etc. That was a set of 4.88 Yukons.
I hear so many opinions on the subject that I think it's a combo of setup and the the really low gear sets for whatever reason. Maybe some "harmonic" thing going on. Either way, I told Brian that as long as it wasn't intrusive where I here it with the windows up....I'm good as long as it doesn't eat itself. I'm just not going to stress over it. I'll break it in as easy as I can, swap the gear oil, and beat on it....just to be overly cautious.