@DanielTepesKraus
The opening story that Twilight read said that Nightmare Moon was banished “forever”. And then some subsequent material she looked up said that Nightmare Moon would return on “the thousandth year” after the stars aid in her escape.
I believe the “forever” part is possibly part of the “general” or “simple” history. The story that’s passed down to children, but isn’t fully accurate. Like how history classes in elementary schools can teach simplified and inaccurate versions of History. They get the major points across, but lots of important details are missed. [Just my theory]
The thing with the stars and the 1,000 years. Implies that there was a set time on when she would be able to escape. Using the positions of the stars as a form of Timer. Since constellations and the like would have shifted in the 1,000 years. [And add some Fantasy world, Magic nonsense to exaggerate their movement.]
So it seems likely that Celestia, when researching ways to help her Sister, found that there was a set time where she would be freed.
It’s possible Celestia tried other methods to free her sister, perhaps while having set up stronger defenses around herself so she could be captured without having to be locked into the moon again or what-have-ye. But found she was unable to overpower the magic of the Elements. Since they’re shown to be pretty much the
top of the power chain so far. But we’ll never know unless Hasbro chucks some more Lore at us~
Though given Celestia’s
canon characterization. It seems reasonable to believe that she attempted/researched the issue and found she would be unable to do anything till the 1,000 year mark.
Edit due to other comments:
The Quest idea and stuff would be awesome. I’d love seeing something like that~