Blizzard has posted an official blog post highlighting the new Warlock races and pet customizations coming in Patch 10.1.5!
In the Fractures in Time content update, the Warlock Class expands to new races. You’ll also be able to undertake a new Warlock-specific questline and use the Barbershop to customize your pets.Embracing New WaysNight Elves, Draenei, Lightforged Draenei, Pandaren, Kul Tiran, Tauren, Highmountain Tauren, Mag’har Orcs, and Zandalari Trolls can embrace the ways of the Warlock class—if they have the keen intellect for it and a strong stomach.Demons aren’t always easy to wrangle.New Quest: New Imp Warlocks can undertake a new quest line at level 30 that starts with the quest «Beginning Impositions.” To get started, meet up with Assistant Phineas in the Mage Quarter in Stormwind or in the Shadowed Cleft in Orgrimmar. He’ll send you on your way—in style—in a carriage bound for the Darkmoon fairgrounds.Denizens of Azeroth, Do you thirst for power? Do you wish to change your circumstances, to become… more? More free.
More respected. More feared.
Do you wish to become a Warlock? If your response to any of the above is „yes“, then meet with my humble servant Phineas. In temptation, Madam ShadowOnce there, you’ll speak with Madam Shadow, who needs your help bringing new Warlocks into the fold.
You’ll meet the new recruits, hear their stories of why they want to become a Warlock and complete the tasks Madam Shadow sets before you as you unwind any new mysteries on the dark isle.Completing the questline will provide a new Imp customization.Customizing Your Demon PetsStop by the Barbershop to view the available customizations in the game for your demon pets. You’ll be able to see the ones you’ve earned or ones.
Read more on wowhead.com