I honestly don't think that Gamestop cared about Xenoblade at all; it coming to North America likely was a combination of having a relatively empty release schedule and fan demand for the title (hence why the North American release was first announced on Facebook, where a large portion of Operation Rainfall activity had taken place). Making it exclusive to Gamestop was just a way of making it more risk free.
While it is very true that 4000 posts does not equal 4000 users, it's still improbable that a small number of users could make that many posts about one game, compared to the rest of the titles on the board. It still shows that at least on that forum, there's an interest larger than the other titles.
And really, it's not that improbable to release here; Atlus is releasing the similar Code of Princess this month, after all. As well as this Aksys is not afraid to release titles like this (shown by their release of games like the Agarest War series), and have already released games on the 3DS. It still has a decent chance, I think.