As of this writing, World of Warcraft has 24 playable races for players to choose from. These races are split down the middle, 12 siding with the Horde and 12 with the Alliance. Every other expansion pack has added new races to the game; The Burning Crusade added blood elves and draenei, Cataclysm added goblins and worgen, and Mists of Pandaria added pandaren for both sides. Legion chose to add a class instead of a race, and then Battle for Azeroth added 10 new races through the allied race system, four of which came from Legion.
The allied race system that Battle for Azeroth added to World of Warcraft makes adding new races easier for Blizzard. Instead of being full-fledged new races with models and starting zones, these allied races are built off of pre-existing models in the game. The vulpera are built on goblins, nightborne and void elves are on night elves and blood elves, lightforged draenei are glittery draenei; the list goes on. While the ninth expansion will most likely add a new class to the game, Blizzard should also consider adding a new race for players to mess around with.
Murlocs
Murlocs are one of the most iconic races in World of Warcraft, and almost every player has the murloc noise engrained into their head. The amount of murlocs that players have been tasked with killing is enormous, and they seem to crop up in almost every new zone. They are simple people who live in huts along the shore and collect fish, but maybe the Horde and Alliance could rise them up to join the ranks of their armies.
Players have taken many trips underwater and recruited various species to help them, including the occasional murloc. While it would take some lore reshuffling and believable writing on Blizzard's part, murlocs could be a unique race to mess around with, providing a whole new set of customization tools. If murlocs do not make the cut, Blizzard could also offer playable naga or gilgoblins from Nazjatar, as both are far more likely additions.
Ogres
Ogres have existed in Warcraft since the first war, depicted in Warcraft: Orcs & Humans. They have been a part of the Horde for a while, lending their strength to orc armies, and one of the ogre clans officially joined the Horde after Cataclysm. They are an integral part of the story of Azeroth, and have appeared in multiple expansions, but players have yet to play as one.
Most of the ogres that players encounter in World of Warcraft are either antagonists or unintelligent brutes that barely speak, but there is nothing in Warcraft lore that states ogres have to be either of those. Their society is based on strength rather than smarts, but so are the orcs who run the Horde. If the orcs can be portrayed as intelligent beings, ogres can too. Allowing players to play as these brutes has been a long time coming, and the next expansion is Blizzard's chance to deliver.
Races from the Shadowlands
Battle for Azeroth introduced the allied race system, which tasked players with recruiting races they had encountered in previous expansions as well as the current one. In Shadowlands, players worked alongside four covenants of different races: the Kyrian from Bastion, Venthyr from Revendreth, Necrolords from Maldraxxus, and the Night Fae from Ardenweald. Players have spent the last two years gaining their trust and helping them rebuild, so it would be a shame to just abandon them once the next expansion rolls around.
Currently, players have no idea how Shadowlands will end, so it is unclear how plausible the idea of playable Shadowlands races is. The concept of the covenants is that they are made up of dead characters from various afterlives, so it would be odd to have these races wandering Azeroth. However, some characters could choose to leave while the veil of death is broken, and canonically players created portals back to Azeroth throughout the Shadowlands. Letting players run around as Kyrian, Venthyr, or even Night Fae would make their time in Shadowlands feel worthwhile, and it would give them some wild races to customize.
Arakkoa
Mag'har orc and lightforged draenei followed players from alternate Draenor in Warlords of Draenor and are now playable races, but an even cooler race was left behind: the arakkoa. Arakkoa were bird-like humanoids who wore ragged cloaks and lived in Spires of Arak on Draenor. They also made an appearance in The Burning Crusade across Outland. The majority of them were hostile to players, but there was a group known as the Arakkoa Outcasts that were neutral.
As far as World of Warcraft races go, there are no avian peoples. Players helped some arakkoa during their time leveling, and now the arakkoa should help players in return. They could be like the pandaren with access to both sides, and arakkoa would open up new customization features involving feathers that could be a lot of fun to mess around with.
Half-Orcs/Half-Elves/Half-Tauren
Most fantasy properties have half-elves and other halflings; World of Warcraft is no different. There are many characters on Azeroth that are mixed race; one of the main participants in the First War was a half-orc named Garona, and many Horde players know Rexxar the half-ogre. While they have played an integral part in Warcraft, players are unable to take on the role of any mixed characters, and as the faction war ends there will no doubt be even more across Azeroth.
The ability to play as half-orcs, half-elves, or even half-tauren, could allow for a whole new level of customization. Players could choose from customization options of two races and be allowed to create the character of their dreams, then join the Alliance or Horde depending upon what races make up their character. It would require Blizzard to shake up the character creation system a little, but this would ultimately make sense in the story of Warcraft.
There are many races that Blizzard could add in World of Warcraft's ninth expansion. The allied race system makes it even easier for Blizzard, and it should take advantage of that when the next expansion rolls around. For now, fans will just have to wait and see what the developer has planned when its next expansion is announced on April 19.
World of Warcraft is available now on PC.