When in doubt, the capital probably has it
In World of Warcraft expansions, the prevalent formula of new content typically includes adding a new capital city. Dalaran was one of the most memorable in WoW history, but Valdrakken, with its emphasis on dragonflight, could approach that realm for some.
Here’s where to find the PVP vendors there.
You can find the PVP vendors in the capital city of Valdrakken, across from the Sapphire Enclave
As soon as you unlock dragonriding in the expansion, you can head to Valdrakken, even before any story-related happenings actually guide you there. Just hop on your new mount, and fly up to the city, which is located in the western end of Thaldraszus. You may need to rest a bit to replenish vigor when flying upward, but you can dive down and ride the wind to extend your flight capabilities a bit.
Once you’re there, go to the northern portion of the city and enter the building directly across from the Sapphire Enclave. That medium-sized area is where you’ll find the PVP vendors, including the Conquest Quartermaster, the Honor Quartermaster, the Item Upgrade NPC, and the Elite Conquest Quartermaster.
You’ll also be able to find the Bloody Token vendor there, named Malicia. That NPC is a grey-colored dragon that’s directly near the entrance.