As I've said repeatedly now, there is no need for these threads, as when someone's birthday comes, there's a direct link to their userpage at the bottom of the forum index where you can wish them a happy birthday via those means.
Birthday threads don't really have a place anywhere, essentially making them little more than spam that clutters up the forum, you can't call it general discussion, because there's no room for discussion, nor does it have a place in the Introduction & Goodbye section, nor anywhere else in the forum, really, if you want to wish somebody a happy birthday, I don't see why you can't do it on their profile, it's significantly easier than doing it through a thread.
I swear if I don't see another Birthday thread, it'll be too soon, thread locked.