What, people with Traveler shit in them...metaphorically speaking. Maybe like biotic sensitive people in Mass Effect the Awoken:!/@:&/8:$:&.&.$zjais screw it I'm done.
I think they're literal children of the Traveler. Beautiful people that were born/came out of her and were raised by humans as if they were humans. That would explain why they're so accustomed to human ways of life.
I have multiple ideas on it but this is my personal best/favorite so far.
I was wondering if the Awoken were some kind of race, 'planted' long ago. Either designed or destined to meet up with us, they have no knowledge of much of their racial history, as an event similar to that which effectively ended ours also lead to the end of their civilization.
The Exo, I think, might have the same sort of background but were a less-highly developed civilization (as arrogant as that sounds) that had mastered the transition from organic to 'machine' based life. And upon meeting us, assumed their current humanoid shape because of our trouble with the uncanny valley.
That being said, I think the Awoken are probably immortal or extremely long-lived (like I believe the Exo to be), as they long ago discovered superior bio-engineering that would allow for such an organism to proactively repair itself. Instead of focusing on an analytical pursuit (which they might have long ago abandoned but no longer remember), they opted for a more existential one based on experiencing being as a 'living' organism would.
Ok, I'm done rambling. Thank you.