The official home video releases contains a lot of deleted and pre-final audio scenes.

I'm not saying he just cut that all together, but if someone did, it might pass for a workprint.

I haven't watched and compared this to the DVD bonus features so I can't be sure. It's also the reason I haven't bothered to watch it yet.

I have no reason to say it isn't legit, but it is not uncommon for fan editors to take liberties in their enthusiasm to recreate a better version than before.

Besides, he insists on calling it a Director's cut, but there is no evidence that Henson and Oz would have edited the original version let alone the version on YouTube. He would have been more accurate in calling it a reconstructed workprint.