Alrighty, there were some issues with Wowheading changing its formatting a bit, resulting in new items not showing properly.

We're in the process of repopulating our database, but in order to make sure we don't put to much load on Wowhead's servers, it's only importing a handful every minute.

Currently, it's estimated to catch up with the requests within the next few hours. The safe assumption is just to wait overnight for item links to be assured to work properly again.