User blog comment:Saratje/PC release date explained - Skyrim: Dragonborn DLC/@comment-58.150.246.17-20130101005642

DLC stands for Downloadable content. Just because Hearthfire was a small addition with no new locations doesn't mean it was not DLC. Dawngaurd was actually the 4th DLC as the HD Texture pack was also Labeled as DLC. Do we lable the CK as DLC too?

The point I'm trying to make is this article does a poor job of explaining the delay. The only reason I would see a delay is like something we see with other games where content is released 2 weeks early. I guess its possible however they ran into too many bugs or contracting deals were not met.