That's a common complaint about collection work. I've heard it about an epic poem we have in Norway (not on the scope of Kalevala), Draumkvedet, or the song of the dream. Molkte Moe published a "restored" version in the 1890s, which I think is very good. But the purists complained that it supplanted the oral versions, of which there were many.

(The final part of Draumkvedet, the "beautitudes" section listing good deeds and their rewards in the afterlife, is conspicuously similar to the Lyke-wake dirge to me.)