So, MoP.
They do that all the time. It's not new, hell Wrath showed us Dance Studio and we've NEVER LET THEM FORGET IT. That's what happens when you get early previews of things, sometimes they don't make the final cut. If you prefer they could only show us things when they're definitely going to be included, a week before patch day, and this website could have tumbleweeds blowing through it half the year.