The intent is to make the distributed version more true to the real original. None of us got to see the original. The original is a bunch of data on various machines. What we saw was a low quality save file of the original, cut down and watered down to the specs of 4:3 CRT televisions and broadcast hardware of the time. That version develops artefacts not intended when distributed on modern media.

Now this probably isn't using original source files but it is possible. Remaster as a term also is used when they take the final master copy and rerun it through more modern technologies to get a cleaner output which is what I expect happened here.

Increased framerate alone would make any CGI content more watchable.