I know many don’t consider SL and its lore canon, and I tend to agree, but speculation is fun regardless, like fanfiction for LoTR.
So, The First Ones, creators of reality, were just the names given to the Titans of the previous iteration of the universe. That would explain why the Oribos First Ones’ architecture is so similar to Titan architecture, and their writing is similar as well. They also have dominion over all the other cosmic forces (Titans of Life, Time, Death, Spirit, Earth, and potentially Void, Light and Fel out there somewhere already awake or nascent, Azeroth is Spirit?) and supreme power of creation and destruction.
The Titan’s are charged as being custodians of reality, as they go around creating, destroying and shaping planets, stars and galaxies. The ensure that no one force dominates, purging worlds of excess influences, creating life, and setting them in balance like on Draenor, Azeroth, and trillions of others at the minimum. (assuming WoW universe is similar in size to ours). Titans were formed at the very beginning of our universe, in the first accretion disks of the first nebula. And also that the Titans were “given wonders by the First Ones.” I believe is referring to knowledge, or a duty, and after the previous Titans (First Ones) had evolved to such an extent they left our reality or something, or dispersed back into our own to become the next generation of Titans after creating our universe.
Also like I said in a General Post we need more female Titans. We have 7 guys (Golganneth, Khaz’garoth, Sargeras, Aman’thul, Aggramar, Norgannon, Argus) and only two girls (Azeroth, Eonar). The Titans of Void, Light, and Fel ought to be female to make up the disparity. Hearthstone already has Amitus, just port her in like other Hearthstone characters that got added.