Do you think that Oryx's homeworld is the same as the fallen? In the books of sorrow, it clearly indicates that there are over 500 races on the fundement, where Oryx grew up. It also states how the Traveler created or caused the "god-wave", which was what Oryx called what I believe the Ellinski called the Whirlwind. After this the travaler fled the system, which prompted Oryx and his sister's to follow it.