There's no real reason for them not to add it to the Mog Station once the promotion is over. At least for European players but ideally everybody. When people urged the company to make region exclusive items available elsewhere in the world they were under the impression that the playing field would be fair. American and Japanese players had a straightforward and accessible promotion. European players did not.
They've already set a precedent anyway - the FFXIII promotion ran more than once in-game and the items associated with it ended up on the Mog Station at a later date.
