
Originally Posted by
Sondrelk
It would however start on the backfoot by having to prove it's a good idea, rather than stuff like the Dragon Isles which conversely has to prove it's not a bad one.
Underground is a very specific concept which the average player likely isnt immediately onboard with, similar to the Shadowlands. It could be good, but it has that extra hurdle to cross.
A world revamp has a whole bunch of fallbacks that it could go to if the actual world revamp isnt all that it's cracked up to be. Several well known locations that could be mined for interesting dungeons or quests. The all important nostalgia factor is very much in play in this case.
MoP is exactly what we are talking about with an underground expansion. Players were against it to start with, and had to prove it was good. Conversely expansions like BfA has more leeway because the concept is so appealing that it had to repeatedly prove it was bad for the mood to sour.
In short: An underground expansion will be a bad idea because Blizzard doesnt have enough goodwill, or enough support around the Underground concept to sell an expansion on that alone.
Maybe if Zaralek cavern was absolutely beloved by the community and everyone were clamoring for more content there. But they are not, most people seem quite happy to leave it behind, even if some people like it. I loved Vashj'ir, but that doesnt mean I think it would be a good idea for a full expansion, just that I would love it.