This is not true at all.
Right there in the Program Terms (top right of the website), it says:
“During the Promotion Period, reward items will be available in limited numbers, and are available while supplies last and are subject to availability (“Rewards”).”
It seems that you, and others, just assumed that your desired reward would be available indefinitely. That was an incorrect assumption.
Also, there is nothing to say they will not restock items. They may just do that, seeing as the promotion runs for another two months. Keep an eye on Wowhead and the promotion website.
, with what are now, to me, useless points. All I can do is keep clicking and hope I click in time if and when it returns.