Because every country that had a release in their national language that is their language. Not English.

Its like a Japanese anime being released here in the states, usually the English track is master audio and the Japan track of lesser quality, the reverse is true in japan.

I believe the japan release will have Japan DTS HD 6.1 MA. In Japanese and the English track will be the lesser encode on there. In mean of course Star Wars. The original Japan release came out in 1978, i have no idea what the special edition dubs were like.