No, I understand your character arc outfits, and those make total sense. I'm speaking more to the choice to make these into separate figures than anything related to the movies.
But maybe Luke's mostly singular outfit in ROTJ forced Hot Toys' hand. What I meant was that ANH and ESB have clearly separate outfits—ANH is clear and for ESB, almost nothing is shared outside the boots/gloves/belt for Hoth Luke/Snowspeeder Luke. But with Jedi it's really just the one outfit, DSII, with extras--for Endor he adds a poncho and helmet and on Tatooine he has a cloak. The figure is just a couple accessories apart from the other, that's all.
Yes, its his base outfit now that he's a Jedi. His new skin I guess that he 'disguises' with different looks for the toys.
But to me, on the shelf, Endor looks different than DSII looks different than Jabba Palace -- he's just wearing black underneath.