I also noticed World Quests popped up everywhere in the Shadowlands, even though I've never been to Ardenweald or Revendreth yet. I've also run into some issues, where World Quests overlapped with my campaign quests, so I wasn't able to complete the regular quests due to phasing, as the World Quest was in the same area as my regular quests. Note that this may be a bug and not intended at all since it's Beta, but it is interesting to see how the rewards and Experience are scaled down to your level.
World Quests popped up for me in Maldraxxus even though I am not at max level yet. The World Quests grant reputation with the new factions, Experience, and gear appropriate to your level. We may be able to complete World Quests while leveling in the new zones in Shadowlands.
