Another thing to think about might be Kennedy.
George personally appointed her as the head of his life’s work; I don’t know if the decision is up to her but she knows how strongly he feels on the matter and might be holding out due to respect on both a personal and professional level.
That’s just speculation though.
All the more reason for them to remaster the SE in 4k as well, which apparently already happened three years ago. George simply didn’t want to spend the money remastering the unaltered versions. Now that it’s not his money being spent, I really don’t see any awkwardness so long as both versions are presented in equal quality (which is exactly what we did not get with the GOUT btw).