Yes, Jeff was working with Gary on the renewal/rewriting of Castle Zagyg, and running playtesting on it with his local group back in the day. Upon Gary's death, the Widow pulled all the IP, and left Jeff High and dry after like 6 months of work without pay. After that setback, Jeff buckled down and wrote Astonishing Swordsmen and Sorcerers of Hyperborea (now just called by most as Hyperborea )
Not sure if they have reached out, nor If they are planning on using any of the content that was worked on by Jeff pre-Gary's passing that he didn't get any pay for, but I'd expect them to in the end finally pay him for his work that he didn't receive recognition/nor compensation for, but I think they may not recognize him for the work he had done, which pisses me off a bit...