About two weeks ago, a few Call of Juarez games, most notably Gunslinger, were delisted from console and PC online storefronts. At the time, we sought comment from Ubisoft, who today sent us an explanation.
"Per the terms of agreement, Call of Juarez The Cartel and Call of Juarez Gunslinger licensing/publishing rights have reverted back to Techland, while others remain active with Ubisoft," the company's PR told us. "This is why a few titles have recently been removed from Steam, but it is our understanding that Techland is working to bring those titles back, so please feel free to reach out to Techland regarding status.”
There are no firm plans in their statement and it doesn't seem to indicate that Ubisoft is seeking to reacquire the licenses and publishing rights involved, so the games returning to digital stores is seemingly entirely in Techland's hands. That said, if you already own the games, you should have no problem redownloading, but new buyers may have to purchase a key elsewhere.
While in principle digital stores should be eternal, licenses and legality means that they can't be in practice. Ideally Techland gets the games back up, but one wonders what happens if Techland folds, or when a game developer decides not to get a license back up.