I think that the devs are not going to stall out primary content for developing the off race genders. If it is going to happen, itll likely happen slowly by the next xpac. The only way I would see them sidelining primary content is if the bean counters and marketers figure that introducing them will net them way more profit. It is unlikely theyll rush it for any other reason. I think the people in the middle on both sides accept this as being the case.