It almost happened in Cata. Ogres were a consideration, but they changed to goblins instead.
But it’s a lot of work making them. Ogres aren’t a reskin of anything. They have to have their whole rigs built anew with player animations in mind, customizations and they don’t even female models either. Plus a story arc for their faction. That’s a lot of time and effort. There hasn’t been an opportunity to fit it in yet.
Maybe eventually though! I don’t think it’s ever been totally shot down, it’s just the stars never lined up right for it.