As I said in some other thread, Lucas was the primary author of both ESB and ROTJ. While directors were basically hired hands to handle principal photography phase.
I am not saying the changes to the films were good. I am just saying that primary author should be the one making special editions. While in many cases director is the primary author of the film, it wasn’t the case in ESB and ROTJ.
Of course they’re hired hands - that’s the whole point. Lucas isn’t the director of those films, or the primary screenplay writer either. He’s the producer. Yes in a way producers are essentially the “primary author”, that’s certainly the case where they take over final cut of the film, impose changes, approve script rewrites, approve sets and costumes, approve casting decisions, etc.
Kershner says in the same interview I quoted from in the OP this:
I turned it down. I told him, “I don’t know anything about special effects.” But he said, “You don’t have to. You think up anything you want and it’s up to Industrial Light and Magic to make it work.” Now, I don’t know of anyone else who could have said that, but he owns the company. So I’d ask for the most impossible shots, and they would do it.
It is clear the director had wide creative control. Perhaps even moreso than most producers would give to directors in mainstream Hollywood films of the time.