R2D2 said:
The OT deleted scenes are muted from time to time without any technical reason. Sound is suddenly off completely in the middle of a shot and on after a few seconds again in the same shot. Technically the sound is either on the master tapes they used or not.
The only explanation I have is Lucasfilm is doing this on purpose to avoid fan films based on those scenes.
It's a shame that fans who are paying to watch those scenes are paying 100% but don't get 100% of their content.
Films at the time were edited on machines in which you had the picture on film on one reel and on another, a magnetic tape shaped like film for the sound. You had to first sync up the picture and sound, mark a big X on the sound strip and film to indicate when the clapboard hit, cut up the shot and hang it on a hook by the sprocket holes in a bin nearby.
Some shots don't even have any on set sound recorded! These are usually 2nd unit shots: cutaways, establishing shots, etc.
So when you're editing, you only have the on set sound. If there is no sound available, you just throw in empty slug to maintain sync.
Lucasfilm isn't cheating you out of anything. I am actually surprised the 2 reel workprint materials still even exist!