Just tried playing this map today via the Steam Workshop. When I first spawn, there's a small obelisk in the middle of the room with 4 glowing green skulls with a faint pillar of light that rises to the top of the room.
There are 4 doors that are wide open that lead to the outer courtyard, presumably.
When approaching those doors, they close automatically and will not open until I reach a far away distance.
How can I get out of this room? No enemies have spawned yet and there seems to be no way to trigger enemy spawns or anything else of the sort.
Best Answer
Watch the first part of this guys YouTube video from around 2 minutes onwards:
coop_mission_haunted CS GO - Counter-Strike Gameplay
Being that it's a coop mission, you need to do it with another player, that seems like the only way to open the doors.
Team-work makes the dream work.