I think Ascension's current situation is no secret to anyone, and it will probably shut down in the coming days or months.
I liked many things about it, and many others I didn't, but if I had to choose one specific element from Epoch to be saved... Orgrimmar.
What's so special about it?
Well, it's ALMOST the same Orgrimmar as Turtle WoW, except for a new Valley/District that was added as extra content: the Valley of the Winds.
This replaces and better integrates the zeppelins with the city, since it was rather silly that the main connections to the other Horde capitals were outside the city. It would be a great addition as the first change to OctoWoW in anticipation of the new content that will be added once the restoration of the now-vanilla content of its predecessor, Turtle WoW, is completed, if all goes well.
I should add that the new area preserves the same textures and details as the original Orgrimmar, so I don't think it would be too difficult to downport it. If it was possible to downport Stormwind from LK to Vanilla, this would be a similar case.
I should add that, given that Epoch will probably be shut down, it wouldn't be a bad idea to preserve a few more small details like that, but my main wish is that Orgrimmar be added to this project.