It does make me much more interested in who Fen'Harel really was, and what he did, and how the title of Dread Wolf came about. Do you suppose we'll get those answers in DLC, or have to wait for DA4? 
I'm afraid that, as Solas put it, "the answers will only lead to more questions"
And in Kotaku Asks they said either Laidlaw, Darrah or Aaryn Flynn said that with upcoming DLC(s) they'll tie some loose ends... but not all of them. Pretty obviously Solas will remain such loos thread till DA4 - though in what way, we're yet to see.
We do see this same pattern of older more primordial titans/gods being overthrown by increasingly more individual gods, representing more complex ideas/cultural functions.
The Forgotten Ones were said to come from the Void, so I think that suggests they were either very old spirits/demons from the time before the veil....or they could have been a younger generation seeking to overthrow their Creators. Either way I think a journey to the Void plays an integral role in this whole individuation and godhood process.
I wonder if this is part of Solas' issue with the Dalish? He's seen it before maybe? Maybe the FO's were counter revolutionaries like the Dalish, wanting to overthrow the Creators to go back to their old ways. Solas himself strikes me as a kind of counter revolutionary, so I wonder if he was one of them for time, as part of their faction/tribe.
I wouldn't be surprised - It might as well be like it was with Greek Gods... again. I mean, Zeus actively got rid of his offspring, if he learned that they could oppose and overthrow him. Ironically, the Olympians eventually became as settled in their cosmic spots and as unwilling to move and make place for new generation as their forefathers (I admit, I'm a sucker for such narratives to a point I've been experimenting with it myself for years now and would be glad to see BWs take on it).
Maybe the reason there was a rebellion was because the previous pantheons, including Creators, eventually failed to move and make space for new generations or only did things to secure their cozy, godly spot, at the expense of others? We may not know this for a while.
In any case, I say that I sense the vibe in Solas/Fen'Harel that may tell me that at least a part of him is very old (maybe because of all those explorations of the Fade or something)... but him, as an individual, doesn't seem to be older than, say, Elvhen civilization itself.
He says, for example, that there were times when elves physically walked the Fade and we see numerous eluvians when we're stuck there - but he himself claims to never be there physically himself. He's too astonished by Inquisitor's post-Conclave survival and his own tumble into the Fade (during Adamant) to lie about that, IMO.
I'd say that he might have been born at the time the Elvhen Empire was either falling apart, or was going through yet another Civil/pantheon war, he learned things in the Fade, found out how it was all those years ago and decided to do something about it. OR... he might have been supporting different people/pantheons throughout ages in hopes that they'd eventually make things better or enable him to turn things to the way they were before they began going awry (for whatever reason).