Eredar are already Draenei in the flesh, just the original race. Man'ari Eredar are just demonic versions of their former Draenei brothers and sisters. So NO, some of the races are going to be left out. Fel Orcs should not be a part of the Horde. They are the hardcore versions and are enemies. The same goes with Fel Blood Elves. Those Blood Elves are the Blood Elf equiv of Fel Orcs. They are damned. Bringing them into the Horde would be hypocritical and would only bring the Orcish storyline backwards all over again.
Why do you think the Horde smacked Mo'ghor out from leading the Dragonmaw? Because he's a Fel Orc that is up to nothing but trouble. Fel Blood Elves were going to summon Kil'Jaeden. Heck even Fel Orcs eventually would fight amongst themselves. If the Horde wants to move forward, they need to abandon the demon blood. Sure there is always going to be Orc Warlocks but they aren't necessarily(Until suddenly Pandaria for some reason that I cannot explain). Blood Elves had to siphon Fel energy to survive. Yes there are Blood Elf Warlocks and are more known HOWEVER they are small and not a big majority. If the Horde again wants to continue and progress they need to put it behind. NOT regress over and over.
That is my argument. Yes we see supposed Fel Orcs at the Dark Portal but that is literally the only place and it makes absolutely no sense. I am betting a lot it was a error(A very LOLWAT) error.
If we're talking about Sub races. Some of them are going to have options others won't. I think the easiest is Dwarves for obvious reasons. I'll get to that. Let me make a list.
Humans- Azotha(Even though I'm not fond of this idea)- High Elves?(Possibly but not necessarily needed), Gilnean Human(You get the starter armor of Gilneans, their voices and such)
Dwarves- Wildhammer,Dark Iron(Earthen? I mean they are allied with us so it is possible. The only issue is the lack of a female Earthen model)
Night Elves- Highborne( This one is also theoretical and I have a hard time thinking what differences so I might need help for that), High Elves(This is the other option I had in mind to include High Elves)
Gnomes- ????(I have no freaking clue, leper gnomes don't seem very nice so...yeah)
Draenei- Broken(They won't be able to play as a Paladin but they can try and be a Nobundo or that shaman dude from Vash'ir)
Worgen- Stormwind/Lordaeron human form(Essentially have the voices of a Stormwind/Lordaeron human in true form)
Orcs- Mag'har(What we all wanted in the end Amirite?), Dragonmaw(Dragonmaw Orcs are still around yah?), Blackrock( Ma'korok without the shitty attitude)
Tauren- Taunka(Those guys from Northrend), Grimtotem( Those that left Magatha), Yaungol may not be possible at all sorry.
Trolls- Non Hunched Trolls(This might be interesting but not necessarily a sub race), Zandalari rebels(Basically you look like a Zandalari troll of sorts. Possible), Other Troll tribes that abandon their dark ways(Gurubashi etc etc)
Undead- Undead High/Blood Elf( If we see those Dark Rangers around, why not be able to be one?) No more that I can think of
Blood Elves- ????????NO NO FEL ELVES. I told you this already. If someone has another idea say it.
Goblin- Yeah I'm out of ideas here.......