This is exactly what happened to me on my ATL-CTG-ATL flights back in January. Full bedding & menus on the way down, not so much the way back. I'm guessing it's because DL only has 3 flights a week out of CTG, so it doesn't make sense for them to have extra pillows & bedding there. So they probably stock the pillows & bedding in ATL for both directions, and there isn't room on the plane for 32 oversized pillows & 32 Westin blankets. Thus, the flight down gets the full treatment, while the flight back gets the standard small pillows & blankets.