The 4K restoration indicates that they have scanned the original elements of the film.
There is nothing to indicate this. Absolutely nothing. The only thing that is public information and known for certain–via Gareth Edwards–is that Disney had a fresh 4K restoration print when he was hired. He did not say whether it was a restoration of the 1977 version or the Special Edition. It could be either one, but it is more than likely the latter. Even if they already did a restoration of the original theatrical releases, but they withhold them for internal use only, that alone would be sufficient cause to criticize them to no end.
The original negative are conformed to the SE, so even if it is the SE it can be called the “original elements”.
Robert Harris is quoted as saying the entire restoration of films like My Fair Lady took less than one year.
That also isn’t as nearly a high-profile a restoration that requires careful timing and consideration.