I agree that the rumour that Lucas has forbid a release of the original versions could be completely unsourced and false.

That said, would this surprise anyone if that were the case? Disney was quite keen on getting Star Wars, to make future films, which was their primary motivation for acquiring the franchise. So if one of George's conditions on the sale was that the film never be released in its original version, or at a minimum that he must approve all future releases of the OT...I doubt that would be enough of a reason for Disney to walk away from the deal. There seems to be a prevailing attitude that once Star Wars was sold to Disney, Lucasfilm gave up any interest in the films at all, and I don't know if that's the case at all. There could be all kinds of conditions to this deal we don't know about.

On the other hand it's also possible that George has softened on the issue. We just don't know.

Now, I have no idea what the deal is, but George wanting final approval on future releases certainly would not be inconsistent with anything he's done before.