Actually I start to believe that
1; maintaining WoW's server park is expensive
2; finding devs who can (and will!) work with the obsolete and veeery old engine of the game is hard and expensive
3; all these technologies which can put servers together, with phasing, garrisons, war mode, etc. can be hard to manage
--> in conclusion, WoW is NOT WORTH IT for Blizzard. They want to kill the game.
All these subscriptions, expansion pack sells, race changes, mounts/pets etc. are not worth enough.
Oh, they do provide income, but other franchises have bigger margins.
They cannot just shut down everything, they need to make the game
-hard to access
-hard to access for new players
-provide JUST ENOUGH to keep you subbed (hello timegating shit)
-etc-etc