Must say, I've never thought of it that way. When I listen with chills running up my spine, to Sweet Honey in the Rock, or to Anne Hills, Cindy Mangsen, and Priscilla Herdman, I think of what they do as fine musical art, and I don't think of them as violating the folk tradition.
Now I have heard people sing folk songs as opera. Art, perhaps, but not my kinda art.