There’s a pinned post David Weber wrote that tells his upcoming works. Of course, that was before the hurricane totaled out his office. As in, it is beyond repair and would have to be rebuilt. He is currently in a temporary office in our Rec room. But he is getting back to work slowly. And he definitely wants to deal with the Gbaba.
At least there's a glimmer of hope that Safehold isn't completely abandoned and that David's interested in writing a conclusion that deals with eh Gbaba!