There's no real indication that the Wormhole is gonna be gone for long, so I don't think the cover is lying, exactly....
The cover is already 'wrong' in that the station depicted is nothing like the station described at the end of the book. So I wouldn't put my faith about future storylines on just one cover.
I do, however, agree that the wormhole probably won't be gone forever. I can understand the how and the why behind for the Prophets. One of the first actions we see them undertake in the pilot, is closing the wormhole, because they felt the presence of this linear creatures was disturbing. After Benjamin pursuaded them, they allowed travel through the wormhole. But after what some rogue elements of the TP tried to do inside the wormhole, perhaps they felt they needed to reavaluate their views on traveling through the wormhole.
I know, I know, it's a very linear way of thinking, one that wouldn't necessarily work for the Prophets. But that's sort of what I feel happened.