I'm not sure if anyone has the answer to this, but why does Lego remake figures like Luke so much? It seems like every year they remake every figure. They even changed Luke's Jedi Knight hairpiece to a different color in the same year.
You can see Luke putting on a glove while flying to Dagobah in RotJ, to cover up the damage done by a blaster during the fight on the sail barge. So, logically, any Luke variant from before that point (Jabba's Palace, Sail Barge) should have a flesh hand, while any after (Death Star II, Endor) should have black.