Here’s a new theory. Perhaps those spirits were only visible to Luke. No one seems to acknowledge them when they appear not even Leia when she comes over to Luke. That said perhaps they appear in a spiritual form that’s only recognizable to Luke. Just because to some of us there may be less logic to have Anakin appear elderly and unscarred doesn’t mean it’s not logical in Luke’s case. Anakin may appear in a form he had not been in his lifetime but Luke still clearly recognizes it as the redeemed man he saw behind the mask.

Having Hayden appear IMO makes Anakins redemption less meaningful and deceptive. It almost pushes the idea that had he survived we are to think he will just return to the whiny young Jedi he was years ago which I think most of us will agree wouldnt be the case. IMO the redemption is more about a man turning his back on evil for good than simply reverting to who he had been many years before. The spirit Luke sees is the redeemed man who saved his life, not the whiny arrogant Jedi who would ultimately turn his back on good.