I would assume Ady will be making shaw the old anakin ghost again.

But if Hayden were to be left in there I thought of an idea to make it work better.

Perhaps at some reflective point in ROTJ Luke could somehow be shown viewing an old photo of his father when he was young. During the time span in ROTJ Luke is heavily thinking about his father and turning him back. It wouldn't be that out there to see him checking out an old image like that as it might be part of his way of coming to terms with his family history.

Then when he sees the ghost at the end it would be a better tie-in.