I'm not exactly sure on that but it's to give the systems time because it may release at different times since there are players from all over the world. It's basically like a Grace Period
Funny you should say "grace"...I'm also sure a.lot of tsw2 players say a pray(If religious in anyway)right before hitting the buy button on the newest dtg tsw2 dlc that whatevers broke won't be found to quickly before they get to play abit of there new route.