Ahem, if you cut off a limb of an ememy it's a killing animation you see. With the VATS system gone there won't be any disabling features "caused by player skill" (e.g. by aiming) anymore in the game. Everything we can hope for now are some predefined, not-skill based animations in fights based on the question whether we used the right oil or not during preparation....
Still sad about the VATS system. Best feature they originally announced for the whole game...
While the normal grunts and bandits won't like have these things, that doesn't mean bosses and monster hunts won't have special weaknesses you can exploit.