Descent: Underground was successfully Kickstarted in April 2015, went to Early Access later that year, and then in September 2017 was taken down so the developers could "focus on implementing single-player, tech trees, and the other cool features we’ve talked about." That was the final update on Steam until yesterday, when publisher Little Orbit dropped a new trailer and said that a Descent beta will begin in November, followed by a release in early 2019.
The beta will be open to anyone who preorders the game, as well as everyone had it on Early Access before it was removed. Early Access supporters will also be given the preorder bonuses now being offered, including a custom "Viola" ship, beta-exclusive challenges, "Secret Missions" DLC, and more.
"This testing window has an important job to do. At different times, we will ask you to try out and give feedback on different aspects of the game, including the single-player campaign. Your feedback will inform our work to polish and refine the Descent experience ahead of our Retail Release," the developers wrote. They also promised to be more communicative now than "open development" has resumed.
As for the slightly-changed name (it's just Descent now), a studio rep said that's intended to more accurately reflect the expanded scope of the project: "Underground was removed from the title during development as the game has become a larger reimagining of the original as a whole and not just an addition."
More information about the new Descent, and preorder links (it's not back on Steam just yet) can be had at descent2018.com.