DLC is a separate piece of content, free or paid, that is an addendum to the base game. An update is a requirement that falls in line with general housekeeping and finishing out the base game (or in this case TTK). This new strike is fulfilling the promises made about TTK according to what Bungie has said earlier. Much like Street Fighter 5's story mode, it's not being given for free, it is completing the game already purchased. It is a requirement to log in. It is not an optional piece of content. Unlike DLC, free or purchasable, I am not getting something extra. I am getting what was promised with the original purchase. I do not go to the store to opt in to this content, it is forced upon me, much like the past updates that took away the old level 28 weekly heroics and nightfalls.