I'm glad to see the studio is doing something about this, which is the worst problem I have ever seen on a DVD in nearly 15 years. That said, I will reserve judgment until I see the replacement disc as to whether it is successful.
I don't know how these things work, but isn't it at least possible that in the process of preparing the US DVDs, they could have said "Hmmm, the sound from the source sucks" and used another source, even the commercially-released R2 DVDs? Who would have known?
I just checked it out, and... It's the worst thing I have ever heard from a DVD. No amount of increased volume helps. I don't buy Universal's explanation. Sounds like laziness to me.