Yea, I assume it means (in this case, not the literal meaning of the word) doing a new version from the original masters, but with a higher fidelity method since it's not something that has to be shipped with a game or played in one, etc.
And I wonder if that's not the normal meaning of the word; I remember at some point seeing a "Digitally Remastered" box set of the original Star Wars trilogy. I assume they didn't re-film
I guess someone still had the old reels/tapes? Of course, they also did some extra post-processing on those, added a big then-modern explosion to the death star scene, etc. So maybe it just sort of means whatever