Honestly I haven't read too much lore but it would be cool if in a future expansion or in Destiny 2 they introduced a whole new group of warriors that don't depend on light and are actually against the traveler and the speaker. They have their own hub where they meet, maybe some rundown place and you can pick from three new subclasses. That would create and interesting dichotomy in the Destiny world. Those who depend on the traveler and those who don't but still find a way to survive.