I am having this problem as well. When I contacted Xbox support they told the "Destiny: The Collection Upgrade" was a timed pre-order and that I can no longer purchase it until the release of Rise of Iron. I think the support rep just read the "Rise of Iron" available on 20.09.2016 and got confused. I have noticed a couple of other threads on bungie.net on other places like reddit with other people in the same boat but neither Bungie nor Microsoft seem to know what's up. I also noticed when browsing the store on my new Xbox One that I can "buy" "Destiny: The Taken King" for AU $29.95. This is despite the fact that I already own it (and have been playing since it's release) because I paid AU $69.95 for it when it was released last September. However I paid for it through the prompt from within Destiny. The current working theory amongst others with this same problem is that purchasing the Taken King in this way somehow doesn't count or doesn't register with Xbox and this is what is causing the problem. When I go to the Xbox store either online or through the Xbox One it isn't detecting me having owned "Destiny: The Taken King" (thus being presented the offer to buy it) and therefore the offer is unavailable. I have deleted my Destiny game files and have started re-downloading them in the hopes this may somehow fix the problem (refreshing the game license?) but my internet is average so it is taking a very long time to complete. I will report back with my findings. Eventually. Until then can Bungie support staff confirm that "Destiny: The Collection Upgrade" should be currently available to purchase and wasn't some kind of wacky unannounced pre-order deal like the Microsoft rep thought it was?