I'm hoping the elven gods stuff might actually be addressed in DLC, if only because the epilogue gave me the impression that whatever is happening with the Wardens might be the main event for DA4. Especially since DA4 is likely to be set further north, so I could see the Anderfels/Tevinter being the setting for whatever is next. Or at least give Lavellan some form of closure before they move on, if Solas' story is continuing elsewhere.
At least the Dalish described Fen'Harel as someone who walked freely among both the Creators and the Forgotten Ones, because both saw him as one of their own. Which does sound a bit like a go-between. Of course the Dalish got a lot wrong, but they may have been onto something there. I have a suspicion that he may have been some sort of military leader/diplomat, which might have something to do with the wolf guardian imagery. I think the "rebellion" association may have come later.
Well, all of the Emerald Knights used to keep wolf companions. Perhaps there was a reason for that, OR, conversely... maybe it's because of that that they deified a wolf?
We know that spirits form based on ideas and ideals. What if the ancient elven gods are the same, and then Fen'harel, Dread Wolf, came into being and was then called and bound into an elven body (or that of a wolf)? It would make a strange amount of sense if the elves once upon a time saw wolves as their brethren the way they see halla in the Dragon Age. And since wolves have long shared an ambiguous relationship with humankind (they became dogs, after all), perhaps elves had a similar relationship with wolves, and thus Fen'harel. He was a guide, a guardian, but also a potential threat that must be appeased.
Ever since someone pointed out that the Lady of the Forest said she was put into the "dread wolf's body"... it made me wonder. Witherfang was male, the Lady of the Forest was female. She said it was because of the duality of her nature, but, Fen'harel is also male.
So here's a strange and most likely completely false theory for you:
Fen'harel is the origin of werewolves in general, and not all of them suffer the way the ones the Lady of the Forest made suffered. Originally he was a spirit, or something like one, put into the body of a wolf. But while he slept, the wolf body was taken from him. He was stuck within the Fade, not that he wanted to leave yet.
Then Solas either found a new host--Solas, born in the Tevinter Imperium--or, conversely, began to become real just as you can help Cole to become real.
Eh, but that's just pure speculation. The only thing I feel relatively sure about is that Solas's original role, prior to being the god of rebellion, must have tied in with the Emerald Knights' wolf companions somehow. It was probably an even older role, since the Emerald Knights came about during the time of the Dales. Unless of course you want to follow the theory that Shartan was Solas/Fen'harel, and they took wolf companions to honor the Dread Wolf, long after the fact. More likely it was a remnant of lore that the Dalish have now lost, and by keeping their wolves, the ancient elves of the Dales were honoring Fen'harel.