if we're being honest.
what lore did Blizzard not expend by turning Legion into a cash grab?
I mean, they injected like every possible loose end into Legion.
now your opinion on legions quality may differ from mine
but the fact is, they expended that lore.
South Seas seems like one of the only decent options right now apart from some weird void expansion, or the "endgame" expansion (Titans, Sargeras)
There's maybe a good chance we'll get the latter now and Blizzard are looking to stop with expansion releases.
If It was up to me I'd just announce WoW II and start fresh.
If I had to work with the existing (mess) game I'd permanently shut down Draenor, redo Outland and some of the worst parts of the Cataclysm overhaul and focus on an expansion that really does feel like it's set in the now combined world of Azeroth (Val'sharah, Pandaria, Northrend) , so sailing between continents and a bunch of new visual
overhauls for the entire game, simplifications across the board.
I'd probably nuke every maxed player down to level 50 so that the expansion would take people up to level 60. I'd design content so that you are hopping between all previous expansion areas, and redo questing in all of these areas, removing bad quests, keeping great or memorable ones. Similar to dungeons/raids.
every player that's currently <= 109 gets placed at level 1 to experience a fresh leveling experience.