The relationship between Sony and Bungie has netted PlayStation players quite a bit of exclusive content for Destiny, including maps. This content is meant to be timed so it is going to make its way to Xbox players eventually, but that may not be for a while. When The Taken King launched the exclusive content was listed as “until at least Fall 2016.”
While that phrase doesn’t guarantee Xbox players would get the content during that time period it was assumed. However now it appears that the exclusive content will not be available until Fall 2017, as the official Destiny site states. It is unclear though whether this refers to just the Rise Of Iron content, which launches in September, or for all the exclusive content released.