Greetings have always been inconsistent. I have only been consistently given a bottle of water on long haul. Advanced ordering is always inconsistent.
About a year or two ago, on my HKG-SFO flight, I was greeted by a FP and given a bottle of water. Then the FP greeted the passenger at the window (the seat between us was vacant). Then she came back with a bottle of water to him. He might have been given a bottle of water because he was sitting next to a DM.