It's the same mix, they just corrected a couple errors in effects placement, IIRC. There was a shot where the X-wings are diving and the music dropped out, which has been corrected. I think the swapped channels are still there though, and the levels and everything are all the same. So, technically, it's not the same mix, but in terms of the discussion with regards to correcting the mix it hasn't been fixed, overall. The only way to fix it would be to re-do it all over again. Something like a missing music channel for one moment you can just add that back in, but it's a whole new thing to actually go back to the mix itself and re-balance the whole film. As far as Lucas and the mixers themselves are concerned, that's how the films are supposed to sound.