When Star Trek: The Next Generation was remastered in HD, it required a) direct access to the film reels, b) complete re-editing of the film from scratch into the episodes, and c) completely new effects, since the original ones had been done on video post-film transfer.
For a sitcom, c probably doesn’t apply, but b and even a are potentially huge costs.
It’s probably a bit more complicated than that.
When Star Trek: The Next Generation was remastered in HD, it required a) direct access to the film reels, b) complete re-editing of the film from scratch into the episodes, and c) completely new effects, since the original ones had been done on video post-film transfer.
For a sitcom, c probably doesn’t apply, but b and even a are potentially huge costs.