No.... doesn't look free to me. I don't own it and it shows as $14.99 if I were to click the buy button. Perhaps it shows as "free" to you because you already bought it.
There is a "spring sale" on Call of Duty on the store though... it says up to 30% off and up to 50% off for plus members. But from what I can tell it's only on select add-ons and COD full games.