Yes, it's between printings. The distributors don't have (published) availability dates, but the Kickstarter rewards are expected to be shipped in November. Given that a copy of Catacombs is available as a part of some rewards, I'm expecting it's next printing will be around then. Hopefully it won't be later. I bought the expansion after hearing that the base game would be reprinted "soon" and have been impatiently waiting ever since.
Is the expansion being reprinted along with the new Kickstarter stuff and Catacombs base game? I don't know whether picking up the expansion like you said is worth doing at this point.