Love is in the Air achievements retroactive?

WoW writes: "If you were like me and had the wonderful fortune last year to complete the Love is in the Air meta-achievement Fool for Love, there is some interesting news for you. Upon logging on this morning I noticed that the achievements for Charming, Nation of Adoration, and Dangerous Love were completed for me on the date I had originally earned the meta-achievement, last year. Is this a bug or Blizzard's way of allowing those of us who already completed the meta-achievement to not worry about the new holiday tasks?"