When did we get a new ( coming soon ) DLC for Graveyard Keeper called Graveyard Keeper - Game of Crone
I'm also not sure about the Soundtrack and Artbook but I think they were there from the beggining.
Not from the beginning. They were added on July 22, 2019 (about 11 months after the game itself).
Ever reliable Mrkgnao always has the answer. Thanks mate.
So this was indeed an unannounced DLC.