The 4 projects most likely are FoA, FF, an RTS that is set in the GD universe, and a horror survival game. Work on the RTS has been officially confirmed many times, but not much is known about the horror survival game. The last info I’m aware of is from 2021 when Medierra said that Grava and Hyboreal are working on it.
That would be the horror survival game that Medierra and Zantai hinted at a few times. I don’t think there’s much info out there other than who’s working on it.