"Just a thought, would Lucas let them do that sort of thing now? I doubt it, what do you think?"
Why not? Lucas used to use the creature shop and produced a Henson film(Labryinth or Dark Crystal I forgot which) and from what I understand is a muppet fan. He also has Frank Oz in all(but A New Hope) his movies. I don't see why he wouldnt he has worked with the muppets and people like frank and jim, it's not like he would suddenly start hating it.