But no, a fat 78 year old man is not a better representation of what his true self would have been. He was put there before the PT when we knew Vader turned young.
He does not fit anymore, now that we've 'met' and seen the real Anakin, it's actually a blooper, an anachronism, to have him there.
And also, Lucas has already explained that the reason for the change was that it was Anakin's inner self that he used to be that turned to the light, not the burned, scarred DV persona. And it's his story, so that's what is canon.
Also, who wants to go through the afterlife looking like Shaw when you could look like Hayden for eternity?
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It's things like these that nearly made me give up on the cause.