It was most likely done a few years ago, while they were working on the Blurays, but not specifically for that purpose. It's actually frustrating for me to have to be so vague, because I know exactly who did the transfer and why, but I'd get people in trouble if I said anything more specific about it! I may never get to hear the results myself, but the original soundtracks have definitely been preserved for posterity—that much I can say with absolute certainty.

I have no information on whether the same has been done for the foreign language dubs, but I would hope so. If they've been digitizing their archives as I've heard, then it seems likely. I don't think they'd go to the trouble of remixing them over again, though, unless they had a specific commercial reason to do so.