Appears from looking at the rul that he's just adjusting the default weights after closer inspection. Only useful when carrying a corpse, really. Not sure if actual weight units matter at all for non-corpses.
Correct. It's not often you're picking up these kinds of corpses either, so it won't change the game much. It just fixes an inconsistency. I noticed it while going thru working on an armor MOD that had a weight value, which will affect inventory weight limit when equipped, but corpse weight only matters if you come up with a reason to pick up dead bodies.
Xcom uses some sort of indeterminate weight system, given that a grenade weighs 3 a sectoid weighs 30 and muton weighs 40 I figured a soldier in power armor(26) shouldn't be outweighed by a sectoid... also not sure why civilian females had weight of 50.