Mill Creek is re releasing the first season uncut in May 14.

Did they actually go back to the original camera negatives?

According to what I've read on a fansite, regarding where they are located:

http://www.voy.com/187956/730.html

Yes. The only person who could do them unedited would have been Michael. As the sole owner, he was the only one who could have for DVD. By the way, NBC probably held onto a set of broadcasting tapes they aired the show on that are locked up in storage, but I'd imagine all the others have been wiped or destroyed in past years. The orignal film and sound materials of HTH and the uncut masters are housed in a vault that Michael had set up in Hollywood.

I found out from TVshowsondvd.com.