The act of opening a door, or a lid, will displace a good amount of air inside the cool box, whether a top lid or front door. The actual air inside has little thermal mass.
If the lid/door opening orientation alone had a huge effect on actual electrical consumption and performance, then chest style fridges would employ a sliding door which would displace NO air when opened and the subsequent marketing would have everyone believing that anything but a sliding door will cause locusts to converge, and red rain fall from the sky and chicken little doing his thing with an amplified bullhorn, in the quest for maximum profit which rules the world.
The reason chest sytle fridges are more efficient than front loaders is not the cold air spilling out with the door opened, it is the fact that it relies on no seal on the coldest part of the unit, the bottom.
The actual thermal mass of the air that spills out of a front loader is so minimal, that I bet it would be hard to measure the difference in electrical consumption, all other factors being equal, from a front loader to a top loader, as long as the user is not the logic immune/ clueless type that leaves the door open while preparing food. Somebody watching a voltmeter has no hope of discerning the difference, unless they really really want to believe, and such people can be convinced of anything, and are usually the loudest.
That said there can be improvments had in improving the door seals, and larger improvements could be attained with a front loader as opposed to a top loader that has gravational assist to compress the seals.
