A Mission of Unity

In addition to being level 120 and having friendly with the 3 factions, you need to progess through the war campaign until you built bases on all three Alliance islands to get A Mission of Unity and unlock the World Quests.

New player, joined when the Shadowlands Pre-Patch came live.. I wasn't able to get to this quest even with the requirements completed that other people have said. Level 50, all 3 strongholds completed, reputation at friendly for all - but still couldn't get it and Bliz support wasn't very helpful with their generic response.

I figured it out though, apparently [storyline=743] needs to be done in order for this to unlock as well, though no other place lists it as a prerequisite.

Did you level all the way to 120 in just one zone because the quests gave enormous amounts of XP and you dinged before you knew it? Were you excited that you made it to max level, ready to jump into world quests and warfronts with all of the other cool players on your server? Whoa, hold up buddy! You might have hit the XP ceiling, but we're going to force you to go back to the other zones you didn't do and grind rep before we let you do anything fun. Oh, and did we mention that thanks to our nifty scaling technology you won't be able to steamroll those areas like you used to? That's right, all the mobs are going to jump right up to 120 with you so you'll spend extra time trying to get all caught up. If you're squishy, you might even die a couple of times along the way! We know you want to get into that sweet endgame action with your friends (you know, the ones you can't see thanks to our equally spiffy phasing technology), but you're going to have to wait a bit longer. There will probably be another barrier to slow you down even more after you do this quest, but we don't know yet because we're still running in circles somewhere in Vol'dun. Don't forget your sunscreen!