Trading Post Event Vendors (2nd Anniversary) - World of Warcraft 11.0.7
Timestamps:
Armor: 00:06
Weapon 01:17
Mount, pets and Toys: 03:12
Traveller's Log rewards: 04:01
Blizzard added these NPCs for this month. They sell some previously sold trading post items well as travellers' log rewards. Take your chance and pick these if you like them as they may never return and even if they do then its probably not often. I'd recommend the traveller's log rewards if you missed them as those were "free" but exclusive to reward track.