I just finished the quest that grants the Dalaran hearthstone, and the NPC that should appear to give me “An Urgent Gathering” (Paladin classhall) isn’t appearing. I can even see the quest marker when I pull up my map - it simply isn’t spawning in. Level 76 paladin at time of posting, and in the “current timeline”.
Any ideas? Have tried logging out, restarting, reloading ui, swapping zones, and doing the beginning quests of the Legionfall campaign.
Bumping this as I am also having this issue 
I had that issue too. I read that Blizzard already address that issue and one of them seems to work for me. Apparently, you have to do the War Within Intro quest line with Dalaran if you are higher level to do the expansion. Do The Harbinger one where you did the quest with Alleria (if you haven’t done so) and War Within intro (quest line on Sillithus to teleport you to Dalaran and do Nurbian Invasion or if you done it before, skip it with Thrall and it should land you to the aftermath of it) continue further into the expansion till you get to where you land on Dor’gal and access to the portals to your hubs and familiarize with the area. That’s how I do it.
So it depends on either or not your character has done the War Within content.