
Originally Posted by
Eosia
When the story allows for it, they will create the new starting area.
Take a look at Death Knights. Prior to Patch 8.3, all Death Knights started out before the events of Wrath of the Lich King. With the lone exception of Zandalari Trolls and Draenei, all the races that could be Death Knights were present in Kalimdor and the Eastern Kingdoms at the time of the Third War when Arthas was active. Blizzard did not give Zandalari Trolls to Horde and gave the Alliance Draenei DKs because it would have been unfair to have Horde have two extra races, said Zandalari Trolls and High Elves, available to them as DKs but Alliance only having Humans/Dwarves/Gnomes/Night Elves. They did this again in Cataclysm since Worgen since they are immune to being risen as Undead and Goblins not so much. And if you roll a DK of any race from the basic 4 in Vanilla to Pandaren in MoP, you still start out in Eastern Kingdoms, attacking the Scarlet Enclave and such.
But, if you create one as an allied race, your scenario is you are a hero that fell during the events of BfA and were risen by Bolvar. This makes added sense with Shadowlands being about the realms of death and the revelation the Zovaal was the ultimate force behind the creation of the Lich King and the Scourge.
The same thing applies to Demon Hunters. We need a reason to need them as a driving force again. This will involve either Illidan returning from the Seat of the Pantheon or, most likely, Kain Sunfury and Altrius decide to start training others to become Demon Hunters. Because, like Death Knights, Demon Hunters are currently time-locked to the events of Patch 2.2. They start out literally as The Black Temple is being assaulted and return to it just after the raid has defeated Illidan. They're then captured and imprisoned for all the intervening years between then and the Gul'dan opening the portal for the Legion at the Tomb of Sargeras, kicking off Legion.
Blizzard has already said that their plan is to eventually have all races be all classes. It just has to make sense to the story. There will be other combinations that present some difficulties like Undead Paladins and such. But they've already taken the first step with 10.0 bringing in the ability for every races to be a Mage, Priest, or Rogue. Others will soon follow as I am surprised Hunter, Warrior, and Warlock are not part of that too.
And no, I don't think we are going to have another 12 year wait between 10.0's launch and Dracthyr being able to be other classes and other races being able to be Evokers.