Theoretical, considering I don’t have money
If I was, for example, Doug Dimadome from the Dimsdale Dimadome…
and I decided I wanted to literally drop straight cash and comission Blizzard to bring Silvermoon/Eversong/Ghostlands to modern standards… would Blizzard be down?
Like realistically, could a superfan pay to fund and/or expedite a passion project? Does anyone have examples of this happening in other games?
I think it’s definitely therotically possible. Also if we go a step further, if a bunch of WoW superfans become majority shareholders then they could probably pressure Blizzard to do things like these.
Hope some of you’ll are getting ideas 
Its not like Blizz is strapped for cash and can’t afford to; they just don’t care enough to.
Resource allocation.
If you can fund the required developer costs, what it would cost to add to the game etc then on top of it provide a monetary incentive for blizzard to do it, maybe.
They would need to obviously look at it and decide if it would be even good for the game.
Following that, ensuring resources aren’t being taken away from elsewhere (hence the funding for extra developers)
I don’t see why not, with enough money.
To some extent, this likely has already been done.