I think something definitive of 'folk' gets lost if the folk artform itself isn't continually evolving and changing - which is almost bound to be the case if you're using traditional material, but not if you're trying to sing the words Dylan wrote the way Dylan sang them.

Everything is change; it's in the nature of the Tao - nothing stays the same & no rendering of a song can ever be the same as any other, especially if you're trying to sing the words Dylan wrote the way Dylan sang them. There will always be a shortfall between the intention and the result; this is the empirical manifestation of the thing; not only is it empirical, it is also ephemeral.

This doesn't make it Folk though, it's just the way things are.