Well, its actually "we held the Fade and the demon's flight so far from our children and from our lives." Not "held the fate of the demon's flight". So basically they held the fade, either meaning they controlled it or they held it back, as well as held the demons flight, which I assume means directing demons away from their settlements/people. If there wasn't a veil at the time, they'd need to be able to do this to survive and thrive, I suppose.
I personally don't quite believe Solas on the elven artifact front. I do believe the artifacts strengthen the veil in the surrounding area, but I believe he leaves out that they do so by weakening it in others. Picture a piece of cloth. You bunch it up in in one spot, making it thicker there, but do so in two spots and you stretch it taut between them, increasing the tension in the cloth. I think that's what the artifacts are essentially doing. It would explain why activating 10 of them results in a quest where Solas is able to predict where a rift is going to occur. I think activating those artifacts is in fact resulting in a controlled ripping in the veil, as opposed to the chaotic unpredictable ripping happening due to the Breach.