hmm, I’ve always liked more magical-themed expansions. I’m not sure I’d be excited for a “new continent, but it’s Australia!”
Pulling an MoP might be a good idea but then again, a lot of its dynamics were copied in BFA. Didn’t go well. And they don’t get close the hype something like legion could generate: Legion made the players fight the most iconic enemy of Warcraft (on par with the Scourge). It also did a lot of context right: city of evil noble elves dealing with corruption, edgy demon hunters, floating city of mages, the archetype of uniting to fight a bigger threat etc etc.
In terms of lore they need to rethink storytelling entirely; a world revamp or an expansion where we explore new things is good. But most importantly have the company take risks and produce new features the players look forward - it feels like the last expansion in which we were promised things was Legion (the DH class). And even in legion the new features didnt feel a huge deal compared to say, all the things we were promised in previous expansions (WoD alone had the likes of the Garrison, a completely new system even if it backfired).
A lot of stuff (t-mog, mounts) feels like it is oversaturated and all over the game. In every new zone since patch 8.1 there are like 10/30 new mounts to collect with random RNG spawn that you have to farm weekly. Not only it’s bad content but it trivializes the reward. Korthia introduced like, what, 30 new mounts? They don’t even have the time to be iconic as you have too many to think about. Too much is not good. Players can’t properly “absorb” it.
They could try with new rewards, or introduce new rewards that complement old objects. Have customizable mounts? Create combat mounts that can fight in the world/in specific arenas akin to a pet battle thing? And so on and so on.
A new world experience, having the chance to use, for example, the WoD leveling experience (the wolf in nagrand was so good!)
Legion wasn’t perfect and indeed, Legion brought huge issues such as the awful class revamp.
But a lot of Legion features were a new thing at the time. World quests were an attempt to revitalize the leveling areas, which were otherwise left empty all the time. I don’t think they are bad per se though - say, the artifact progression actually made sense at the time, and people were invested in their weapon.