Microsoft has just announced that DLC will be arriving first on Xbox platforms again:

Call of Duty: Advanced Warfare, developed by Sledgehammer Games (co-developers of Call of Duty: Modern Warfare 3), harnesses the first three-year, all next-gen development cycle in franchise history, and again brings all add-on content first to Xbox.

We sort of saw this coming when Activsion posted that teaser clip yesterday with the Xbox One logo…

SOURCE: Xbox Wire – Major Nelson