First, thanks to all who commented or at least read the idea, I respect your opinions even if you like or dislike my idea. Just wanted to make this clear from start since I will attempt to explain some things and I don't want you to think I'm super defensive or something. I know my idea has flaws. But there are some things which I made on purpose some way, and that was what I explained.
Now, at a glimpse, looking say at the Horde races, who would you say is the odd one out? You could say blood elves because they're nice looking, but in terms of lore the odd ones out are the forsaken. Why? Because they're the most grey race there, only in the Horde for their own goals and yet scheeming behing everyone, they're like the black sheep. But does she Alliance have a bad sheep? Not really... I mean the dark irons entered the fray, but they seem to have become nicer... night elves don't follow their own ends along, worgen partially but not really...
But let's think of etheral elves. What are they? They're a part of the Alliance that was lost, they were tortured, experimented upon, and now, when finally they hope to be back to their lands and everything to be happy again... it isn't. They find out part of their race was exterminated and most of the remaining ones joined their former enemies, the trolls and orcs and now suck fel magic from beings. Furthermore, they kicked those that wanted to remain pure! In a way, if you think about it, this is similar to the forsaken idea, the major difference is that etheral elves... do not live on their "ancestral" lands. Because blood elves live there and for now they lack the power to force their way back in.
But on the other hand, I also talked about a gray race. So the etheral elves join the Alliance, but why? Because it's the lesser of two evils. "wait, what?" yes, think about it this way, they have to chose between their former enemies and parts of their race that backstabbed the ones who remained pure and... the Alliance who also backstabbed their people. In the end, was it not the Alliance that sent spies in Quel'thalas when the blood elves reopened their borders? Was it not the Alliance who sent the night elves to sabotage their sanctums? So then, why would the etheral elves trust the Alliance? In the end, the Alliance betrayed them as much as their blood elven bretheren betrayed the remaining pure high elves in their view. The only difference is that the Alliance accepts them in their lands because of Turalyon.
So overall, the etheral elves would hate the Horde, for they are their enemies, trolls, orcs, fel suckers... but they wouldn't love the Alliance much either, in the end the Alliance did not help their people why they were gone, they spied on them and put stops in their track.
But bringing etheral elves and making all remaining high elves into something like them would have a further benefit. Which unplayable race got more lore then some playable races for the Alliance? The high elves. I mean, they were there in Wrath, they were all over, they were there now in MoP, they were there a bit even in Cataclysm. By finally giving a version of high elves to the Alliance you're also giving them some lore from before.
So overall, the etheral elves would not excel for being super mages, they'd excel in bringing that grey element to the Alliance, an element which no other race brings right now. It would make the Alliance less "oh, we're the good guys".
The etheral elves would be just damned high elves, and they would act like such. Could you say the forsaken don't share some human lore? Well of course they do! Yet they do have their own, they grew from that lore to what they are now, similar to how the etheral elves could do the same.
I admit, I don't know how the ogres could grow... I'll need to think of that.
And a disagree a bit. Besides blood elves and goblins, who are everywhere... you also have high elves, who are also everywhere only not part of the Alliance. By turning them into something different model wise but keeping their lore you'd have a race that still is everywhere, is playable, is in the Alliance and furthermore is attractive for they're not just refurbished blood elves.
I already explained why I don't think high elves could be an Alliance candidate. They're just blue eyes blood elves. That's why etheral elves are high elves, only different looking and with some growth in their lore. I could say the same for ogres, though I do admit, there are some races with good lore too around, like naga, nerubian, etc, as you mentioned, you're right there.
So overall, these are not new races, these are new models of high elves and ogres, races which already have lore and connection to both Azeroth and Outlands. The difference is that high elves would not be accepted, because giving them as they are would make some people say "why do the Alliance get a refurbished race and the Horde a new one?" while giving them to the Alliance and not giving any race to the Horde would make the Hordies say "why does one of our race turn neutral, what do we get in return?". Furthermore, it would make a lot of current blood elven players, who rolled blood elves only because high elves were not playable, roll high elves now.
If you give the race with a different model, it's not a refurbished race, the Horde can get their own unique race too, and not all who wanted high elves would reroll etheral elves since it's not what they truly wanted, thus still keeping the balance.
That said, I respect your opinion, just that this is how I see the issue.
That said, I don't want high elves either, mostly because they'd be the same as blood elves, if they give us current high elves... so I thought of an idea to make them different in looks while still keeping their lore. Because, let's face it, even without them being playable, they still get quite a few content around.