To clarify my post, yes, the ogre masks were red herrings and meant nothing about the expansion at that point. However, they weren't just any random thing thrown together. The male ogre is just part from a texture, but I have yet to find where the artwork that female ogre face comes from. I own all the RPG books and it's not from there. I admit, it's an assumption, but the fact that they later said they were considering ogres (and saw females and two-heads as challenges) before settling on goblins, makes it sound logical to me that the female mask comes from a piece of concept art they did when throwing around ideas on what the females should look like.
But my guess was a bit larger than that (and I stress the guess part). Apparently in the past they listed nagas alongside ogres as races they'd like to try to do at some point. I have a suspicion (again, just a suspicion based on vague ideas, not real evidence) that the red herring masks, while definitely red herrings, were at least partially a development in-joke, being based on races they've been considering (and at least one of those seriously considered for that very expansion, by their own admission).