People get upset about this kind of thing, but they also forget that it takes about three to four months from completion of a game for it to pass cert and make it to store shelves. Moreover, the last month or two before that are almost certainly done with a smaller team to reduce bug churn.
Meaning: DLC, a product with no RTM time and reduced cert time, can certainly be about ready to go without having impacted or been cut from the primary product.