Creating images digitally and then storing them to return to them years and years later i hear can be a pain in the neck.
Supposedly CBS digital will have their hands full if and when they decide to revisit Star Trek Deep Space Nine and Voyager.
All the CGI has to be re-rendered in HD.
Not sure if Disney is the same idea.
What about Disney/Lucasfilm they could re-render the horrid star wars prequels for higher resolution but the price tag would not be worth it.