Well, so far we know that after you die you enter purgatory, but i think there is another way. The after life is going to play a big role in not only the easter egg, but in regular gameplay as well. It would be dumb if you had to kill yourself to get in their everytime. So maybe you can sit at one of the various tables around the map with the skull and candles to enter. You wouldnt kill yourself, but your character would sit there like he is afk. This would also explain why in the trailers you see the characters sitting on the ground doing nothing