"Folk" is the bag that reviewers use when they can't put a specific label on the performer.

"Folk" is one of the labels that bands attach to their adjectival list, because they think it will pull in Folkies as well as punkabilly or rock-o-funk afficianados. Other mishmashes are available.

It is a sign of "fusion" music if you are kind, and imprecise focus if you are critical.

It is a current trend/fashion, as I perceive it, and given a the distance of time it will fall inevitably in the bag of "Folk Process".

But at least, with Olivia Chaney, it sounds as if there is a competent performer who, given enough listening, would do justice to a "Folk" song. Or one I (or you, or a critic on the New Yorker) would class as Folk.