Many of us are having this issue, however no one with authority has offered any help :$ Seeing as this was a main reason for many of us to pre-order the game or buy special editions, it's a shame that the community management regarding the leap to next-gen is so poor
Are you still having issues with the Ghost mask transferring over to the Xbox One? Can you clarify which mask you are referring to? Is it the Classic Ghost mask from the gamestop preorder (aka the Simon "Ghost" Riley mask) or the Team Leader Ghost Mask which was part of the Team Leader pack? Did you try uninstalling the game and reinstalling it, then check to see if it is available in the marketplace or on Xbox Live website download history to remotely download to your console?