I can sort of get them reusing the same sculpt for essentially outfit changes within the same movie, but using them to represent other movies isn't on. Three years passed between each and they all looked different. And as Tali mentioned, some weren't the best likenesses to start with. I think Leia is the only ANH likeness I'm really happy with. The rest could have used more tweaking. If they do a Red 5 Luke they better not reuse the ANH sculpt (or the RotJ one).
Really hoping for a Red 5 with a new farmboy sculpt. Would be pretty lazy/cheap after all this time to just plop that original one on there.