I didn’t notice until everybody was unlocking flying in Zereth Mortis by completing the “Secrets of the First Ones” achievement. When I looked at the achievement requirements, I saw that I had not completed “Starting Over”.
I double checked with the in-game script recommended by Wowhead to see if I’d completed the quest: /run print(C_QuestLog.IsQuestFlaggedCompleted(64879))
and I have not completed the quest nor any of the quests in that quest line. It is also unavailable to me, though if I’ve completed later stages of the campaign (everything else in “Secrets of the First Ones” is complete.)
It would be nice not to be forever locked out of flying mounts in ZM! Any help much appreciated.