I would agree that the trials is a tougher version of the crucible, meant to find the best of the best, to prepare for the toughest fight to come. When the queen has skolas (the second time), skolas makes mention of oryx (light snuffer) to variks. The queen sends out two crows as a result, one to Mercury and one to her new ally in the tower. The new ally is Eris who has been actively recruiting the queen for the fight vs oryx. And Mercury? The lighthouse. The place of the best guardians the trials has produced. They'll need them for oryx