I have to take issue with that, because I think it doesn't make any sense.
If you are referring to a younger Anakin put in the ghost scene, that totally dispels the point of ROTJ. ROTJ is about the redemption of Darth Vader, and how the older Anakin, is conflicted thoughout the movie, and finally saves his son by killing the Emperor. By showing an older Anakin standing there next to an older ObiWan, you see the character come full circle, as his redemption is complete.
By changing the ending in the SE with Hayden in the ghost scene, Lucas says that Anakin died on Mustafar, which would totally contradict ROTJ since it was the OLDER Anakin who was conflicted, it was the older Anakin who killed the Emperor, and the OLDER Anakin who tells Luke, "Tell your sister you were right...."
By saying Anakin & Vader are two different people misses the point of ROTJ because they are ONE person the whole time, and even though he went by Darth Vader throughout the OT, there was always was that part of Anakin, the good guy that never left.
Even Lucas doesn't even understand the original story he wrote back in 1983, just so he could stick some gimmick in the 2004 DVD's and try to tie the trilogies together.
You are 100% spot-on. This is what I've always said to people that claim putting Hayden in there makes sense. Not only does it NOT make sense, but it completely undercuts the point of the entire movie. The whole point is that Anakin was brought back to the good side before he physically died... "For once, let me look at you with my own eyes." It's crystal clear. You're right, it's just mind-blowing because it's like Lucas forgot his own story, practically the most important part of ROTJ.