If Yes/No, what existing lore could support it?
Since WoD I had hopes that “Corrupted” but liberated Eredar could join the horde (Red Draeneis)
But that never got any close to happen.
Right now both factions have most character models, I don’t see why not anymore…
Personal opinion: No.
I don’t see Draenei and their variations as a valid Horde race.
There is too much conflict from the past between them and the orcs, that would justify them joining the Horde.
I could see a small group of survivors from Argus who were seperated from their kin and developed their own culture after they settled ‘somewhere’. Those people wouldn’t have the history with the orcs.
But…
If they do, make them a draenei offshoot without those disgusting tendrils and hooves. Please. 
Hell NO.
The alliance can keep their filthy space goats. After all, they are just a lame excuse to give shamans to the alliance.
So… we dont need them…
I don’t think any of the original Orcs of Draenor are still alive and kicking from the Old Horde that attacked Azeroth and commited those hineous crimes against the Exiled Eredar on their shared planet 
If any old timer is still alive, please correct me
So while the Exiled are a long lived basically immortal race and it is easy to hold grudges, it would be no point to hate the present day Orcs for the sins of their parents and in the Dragon Isle with the Dragonscale Expedition for example we see Orcs and Space goats working together, even friends
That’s not an excuse really for me.
Just look at RL tensions going on in the world between people because of something that happened in the past and the original people are no longer alive.
I don’t see that behavior any different between the races of Azeorth.
…Just look at the grudges the night elves and other elves are keeping…
Looks at Velen
I think the Exiled are a bit different… but I guess you are right
None of the flavours of draenei would be welcome for the horde
The horde doesn’t like warlocks because of its history with the burning legion, “repentant” eredar are only really tollerated by the draenei themselves, if at all to be honest. Any other race or faction considers them full on demons which means they are kill on sight
WoW might have become a themepark MMO, but it is still narratively driven.
The reason no is because it makes no sense lorewise
No, just no, after all whad the orc did to the danrei, no
The is no chanche tehy wpoud join them.
that woud be a lame excuse and woud open door for anmy race havinh that one grpou that is different and coud join up the opposite faction.
At this point with how the Game proceed i expect a whole Merge with next 2 expansion .
The game lost the prestige of Alliance Vs Horde …
Even the Lore has been altered to please the development of a neutral World of Warcraft at the point that every Zone-quest-npc is Neutral .
In recent interviews they have hinted at conflict returning between horde and alliance and how they know a lot of people want a return to that formula
personally there’s a side of me thats thinking they’re saying it to keep people invested, I’m at the point of I have to see it to believe it first because of the many weird plot contrivances they’ve already put in place in order to remind us that yes, peace was made and yes, it happened offscreen during a timeskip and we want you to pretend it has already happened and forget all the grievances that were before
Tess greymane my daughter not even the writers felt right with me forgiving the forsaken so instead of writing plot for it I’m just going to abdicate the throne to you
Good thing you already had a girlboss moment with Calia, the least favourite (yet somehow most well known) member of the desolate council. Now worgen and forsaken can be friends.
Any capital, Belameth, Gilneas, soon Silvermoon, should be exclusive to the factions they belong to in my eyes
it could be anything now. since factions now are somethin “ancient” and not so important in blizz lore.
I wouldnt be surprised if they reunite factions in 1 big faction fighting just for sport in arena (lorewise ofc)
Eitrigg for example. Literally any of the older orcs. Just about any of the elder brown orcs, playable or otherwise…
I would rather see new races added rather than just giving the opposite faction a recoloured version of what the other has.
I’m sure the draenei can’t wait to join the faction that has tried to genocide them twice so far.
With cross realm and cross faction guilds in TWW does it really matter what faction you are on. Just play the race you want to play.
I guess everyone is missing the point where I’ve suggested that Corrupted Eredar could join, the guys that split from their group long ago and are mostly Fel now.
Not the blue light worshipping goats.
Exactly. It’s like why Humans and Orcs never will be both on one playable faction side.
Yeah, sure… The Eredar that destroyed Draenor for the most part by corrupting the Orcs via Guldan surely will be most welcomed by the Orcs of the Horde… 
Edit: If certain people want to have a game where everything is possible, those better pick up Baldur’s Gate 3 where they can be literally anything they want. Or similar games.
Devaluing the charm of an RPG by taking away RPG limitations makes it not always better.
Draenei should never be horde, full stop.
So… not Draenei at all, then?
“Yeah, i want gnomes, but not so short, smaller heads, and more serious, also Orcs, but without the green skin and the tusks, and Tauren too! but without all the cow bits!”