One could perhaps think of it as a 'place-holder', more or less of what Camiie was saying I guess.
Something that is easy to remove/modify and which could possibly show future issues before it would become an actual issue.
On the test-server the job list at Status -> Job Levels is also different in size (or at least was the last time I checked, and seems like it can't be extended in a downwards motion but instead, it is wider (or was, haven't checked for a while now) though of course this does not explain why they're sort of there in the 'real' client at all).
They could also just enjoy teasing you all. ^^
Edit:
Oh, and it's entirely possible for someone not to know of the expansion, hence another someone mentioning it (serious or not), leading to the “of course I would know about it” leading to the “how should someone know you know”, you know?
Or at least that's how I see it.