Hey, Caddius, did you also happen to take a closer look at the Song of Elgar'nan you find at the Temple of Mythal? Now that we can confirm Titans to be a thing, how do you suppose this ties into the "hunting the Pillars of the Earth" bit of a different codex? Forgotten Ones, Titans, the possible sheltering of Forgotten Ones by Titans.. This is just like that one time everyone thought elves caused everything. 
Elgar'nan, Wrath and Thunder,
Give us glory.
Give us victory, over the Earth that shakes our cities.
Strike the usurpers with your lightning.
Burn the ground under your gaze.
Bring Winged Death against those who throw down our work.
Elgar'nan, help us tame the land.
I shall deconstruct the song for you.
Line 1: Elgar'nan is the master of skies and of weather. This could imply that Elgar'nan's skill in primal magics as well as possible control over high dragons.
Line 2: Those who worship Elgar'nan wish to gain power from him.
Line 3: Implying that the Titans are stirring up and causing trouble; hence, the prayer to Elgar'nan.
Line 4: More evidence of Elgar'nan's mastery and power of primal magics. This could also be a reference to Elgar'nan as a Zeus-like figure.
Line 5: Elgar'nan is also gifted in elemental magics, hence the word "burn". It could also be a reference to hurting the Titans with magical fire.
Line 6: Winged Death here either refers to High Dragons or to Griffons or perhaps both. "Throw down their work" could be references to earthquakes that sink the livelihood of Elves in the ground.
Line 7: Implication that the land is unstable, experiences of possible earthquakes due to Titans; hence, the request to Elgar'nan to tame the Titans, most likely by killing it.
This song is one that is, in my opinion, entirely devoted to the ancient Elves having trouble with Titans (perhaps they upsetted the balance of the Fade forces ?) and imploring Elgar'nan for help. Whether Elgar'nan responded or not is another question entirely.