I just recently decided to go back and unlock the Nightfallen Allied Race. I finished the Suramar quest line (11/11), and I’ve reached Exalted with the Nightfallen. However, it seems I need to get the Insurrection achievement.
When I go to First Arcanist Thalyssra to start the quest line she doesn’t have a quest for me. I do not have any active quests (I cleared my quest log just in case I was holding onto an active quest), and I haven’t achieved any part of the insurrection achievement, so I don’t believe I’ve partially started the quest line. I’m not sure how to proceed.
So Vanthir in Shalaran didn’t have that quest line for me, which the NPC all the videos I saw on YouTube had me talking to. I found that quest in Suramar while doing world quests and that fixed it for me.
So in short, yes, this was the issue for me. The quest just didn’t start where I thought it did. Thanks for the help.