My main completed the BFA Campaign quest line and can visit the BFA Arathi Highlands.
My alts can see AND interact with Zidormi in Tirisfal. She has a chat bubble on the map. My alts can see Zidormi in cata Arathi Highlands, but cannot interact with her. Zidorma in Arathi does not have a chat bubble on the mini map. When I click on her, her dialogue opens with some text, but there is no option to change the zone.
From what I can gather, the following is the quest series to open it
For your alts, it may hinge on completing the old Cata openers to get things phased properly? Give the suggested bit below a try, see if that does the trick to get her out of that particular phase.
Quest Checker says I’ve completed that quest.
Have your alts unlocked BfA World quests? I seem to remember that being a requirement to start the Warfront stuff… (And they’ll need to pick up the Heart of Azeroth to do that — talk to the Earthen Guardian NPC near the Zuldazar Harbor flightpath or just outside the Boralus Inn for “A Dying World”.)
This was it. I had to get the boats to spawn in first though.
So to I finished Welcome to Zuldazar then the Zandalar United Quest was available from Nathanos on the boat next to the dock portal in zuldazar.