I’m afraid that’s an impossible request, you might consider lowering your standards just a little. You’re basically asking Blizzard to make two expansions simultaneously.
No, they did not have a separate story, they had separate HUBS, which is different. Ultimately, they were all still the same story.
Also, pretty much all of the expansions you listed except for MoP are considered to be terrible from a story perspective, so maybe they shouldn’t listen to you.
If I recall, the High Elves taught humans, the Arathi (prequel to the Alliance kingdoms) how to use magic in the Troll Wards. This was way before BE and the horde existed. Therefore: High Elf (Alliance) + Human (Alliance) = Half Elf (Alliance)
You people need to understand that factions don’t matter. You will take quests from Anduin/Alleria/Jaina, because you care about protecting Azeroth, and right now they are the only ones who can do it.
I am pretty sure that said hubs and quests provided separate story. Like Horde aiding Frostwolves, and Alliance aiding Draenei.
Becuase Alliance couldn’t quest for Frostwolves to reclaim the Ogre Fortress. So by definition it is a separate story and separate experience unique to one faction only.
And what I’m and other people are asking is just to continue that tradition.
Just throwing this out there; we allied races are not officially part of the Horde or the Alliance. We’re friends of the faction. The Vulpera and Zandalari, for example, never took the blood oath to join the Horde. Funny how the Taunka did back in Wrath but never became playable