Not really. Just read how the fall of Arlathan is described: "You ask what happened to Arlathan? Sadly, we do not know. Even those of us who keep the ancient lore have no record of what truly happened. What we have are accounts of the days before the fall, and a fable of the whims of the gods."
"As to why the gods didn't answer, our people left only a legend. They say that Fen'Harel, the Dread Wolf and Lord of Tricksters, approached the ancient gods of good and evil and proposed a truce. The gods of good would remove themselves to heaven, and the lords of evil would exile themselves to the abyss, neither group ever again to enter the other's lands. But the gods did not know that Fen'Harel had planned to betray them, and by the time they realized the Dread Wolf's treachery, they were sealed in their respective realms, never again to interact with the mortal world. It is a fable, to be sure, but those elves who travel the Beyond claim that Fen'Harel still roams the world of dreams, keeping watch over the gods lest they escape from their prisons."
"Whatever the case, Arlathan had fallen to the very humans our people had once considered mere pests. It is said that the Tevinter magisters used their great destructive power to force the very ground to swallow Arlathan whole, destroying eons of collected knowledge, culture, and art. The whole of elven lore left only to memory."
The entire entry is pretty clear that not only do the Dalish have limited knowledge, but that it's possible this "legend" could be entirely wrong. I'm honestly surprised that some people feel like the Dalish can't admit when they're wrong when they willingly admit they could be wrong about why Arlathan fell, or what happened to it after it fell. Keeper Gisharel makes it clear that it's only what's been told, not what absolutely happened beyond a shadow of a doubt.
I know they have limited knowledge, but as much as I love the Dalish there are plenty of them who are very close minded.
And some are not, like the Lavellan clan, it really depends on who you ask.
They have a general opinion of the Dread Wolf and it's a really negative one, it can easily create tunnel vision that blocks them from seeing what's in front of them. They act upon these legends, they wear vallaslins, they curse by the Dread Wolf's name, that's enough to show their beliefs. Maybe the keepers are moderate and have a flexible mind, but the simpler elves? Nah. That's how it is in real life as well. The wise tend to see things in less black and white, and are open to new ideas, the extremes are more common amongst the less knowledgeable.