It's meaningless in the traditional sense, as it has nothing to do with relatedness or Faerie, since the only commonality between the various types of Fae is that they're not human. Even the "light" and "dark" sides are only alignments for personal advantage (a deeply cynical outlook), roughly congruent to whether one is reluctant or eager to kill "humans." I think the writers just liked the *sound* of the word "Fae."

Just saying….

Puddin'