This has to be appliance industry nonsense.
I have an extremely reliable 35 year old (80's) Whirlpool 23 cu/ft top freezer refrigerator that uses 135 running watts. I also have an 8 year old GE 18 cu/ft top freezer refrigerator that uses 130 running watts. The defrost timer is about 18 hours run time on both of them. It is interesting to note that the newer GE uses almost double the watts of the older Whirlpool during compressor startup. Unless they are using much better (more efficient) insulation now days, this claim is obviously false because the wall thickness is the same on both of them.