Lore
Who the Skyborne are, what happened in Eldre'Thalas, who sat in the Barrow Deeps for ten thousand years and which campaign decides where Forever begins. The parts that stay true after launch.
The Skyborne and Skywall
A new playable race whose history is older than almost anything else in the game: exiles from Eldre'Thalas who made a pact with the wind spirits of Skywall - and whose own name gives away where they came from.
The Shen'dralar
Those Who Remain Hidden: Azshara's own arcanists, a city that survived the Sundering, a demon chained in a basement - and a ruler who thinned out his people so the magic would last longer.
Who was imprisoned in the Barrow Deeps
Forever's max-level raid sits in a cave system under Mount Hyjal that Warcraft has used before - as the cell of the most famous prisoner in night elf history, and as the reason an entire order of jailers exists.
The Al'Aketh
Three groups fight over a failing island, and only two of them are a choice. The third worships the Windlord, wants the pylons down, and is the reason the starting zone has a plot at all.
The Forsaken Kingdom campaign
The campaign that decides where Forever starts is not in Forever. It is in Warcraft III Reforged, it is about the Forsaken taking Lordaeron, and it sets the date on the clock the whole game runs on.