Well in terms of the quality of the songs as music, and the singers as music-makers it doesn't matter at all, so all we need to do is make sure the songs are sung (and to respect the singers interpreters though the years and the original writers).
But - and it's a biggie - folk music has an element of 'musical archaeology ' (which is sometimes as or even more important than the quality). So just as the Time Team must record as they dig and know what it is they are looking at, so we need to know how these influences work if we're to track back with any reliability.