A Found Memento

When you finish this quest, the next one is: Summons to the Keep - Summons to the Keep
You will need to wait daily reset and head back to Deliverance Point, You will see Stormwind guards waiting for You. You also see the quest on Broken Shore World Map.

The quest item "Battered Trinket" is under water off the southern tip of the Broken Shore at 53.35, 80.43. It will show up on your mini-map as a !.

It will give you the quest "A Found Memento" which you turn in to Anduin Wrynn in the Stormwind Keep for an AP item that gives 2.1 million AP with AK 30

If you can't see Anduin in the Throne room. You might be phased for stormwind for 3 or more other questlines. If you started any questline that is phasing Stormwind, you need to complete it first, to bring you back into the correct phasing.

BFA 8.1 Questline for Darkshore

If you started Darkshore Warfront questline On Whispered Winds, you must finish the entire questline finishing with We Are Coming

Macro to check: If any of these show "true" (but not all), click the link above for "On Whispered Winds and complete the missing "false" quests (full questline is in the comments). Stormwind should be back to normal afterwards.

/run local a={53847,53849,53988,53989,54041,53990,54871,53992,54006}for i,q in ipairs(a)do print(format("%s: %s",i, IsQuestFlaggedCompleted(q) and "\124cFF00FF00Done\124r" or "\124cFFFF0000Not Done\124r")) end

"The Hand of Fate" Questline.

Check if you got the questline or any of the followups from The Hand of Fate

Macro to check: If any of these show "false", click the link above for "Hand of Fate" and complete them. Stormwind should be back to normal afterwards.

/script for q,i in pairs({["The Hand of Fate (1) ="]=47221,["The Hand of Fate (2)="]=48506,["Two If By Sea ="]=47222,["Light's Exodus ="]=47223,["The Vindicaar ="]=47224})do print(q,IsQuestFlaggedCompleted(i))end

"The Legion Returns" Questline

If you did not complete the initial Legionquestline, then Anduin is not king for you yet and thus you won't find him in the throne room. Check this questline: Legion: The Legion Returns

Macro to check: If any of these show "false", click the link above for "The Legion Returns" and complete them. Stormwind should be back to normal afterwards.

/script for q,i in pairs({["The Legion Returns ="]=40519,["To be prepared="]=42782,["The Battle for Broken Shore ="]=42740 ,["The Fallen Lion ="]=40517})do print(q,IsQuestFlaggedCompleted(i))end

The followup required the full extended questline by the way:

Legion: The Legion Returns
To Be Prepared
The Battle for Broken Shore
The Fallen Lion
Demons Among Us
Illidari Allies
Protect the Home Front
Calling of the Council
The Diamond King
Hiding in the Stacks <- This wil unlock Summons to the Keep at [npc=120281] at Broken Shore Deliverance Point 42/60 (assuming the daily quest reset already happened after A Found Memento was completed)

"Sizing Up The Opposition" Questline

You can't be on Sizing Up The Opposition either, this will phase stormwind as well: /run print(IsQuestFlaggedCompleted(47473))

Good luck

Edit: Added two more possible phasings and macros to check
Edit: April 2019 Added BFA Quest