It is working on Sea of Sorrows. We killed Balthazar last night. The event chain has an insane amount of work to get it started and the balthazar fight is the most epic I have had in the game so far. We failed the first time then had to redo it (about 100 people were fighting him).
As of 10 hours ago, the “Escort the Pact” event got stuck, and the event is now bugged.