Their explanation for vanilla servers doesn't make ANY sense."Why not just let Nostalrius continue the way it was? The honest answer is, failure to protect against intellectual property infringement would damage Blizzard's rights. This applies to anything that uses WoW's IP, including unofficial servers. And while we've looked into the possibility-there is not a clear legal path to protect Blizzard's IP and grant an operating license to a pirate server."
The post also states that Blizzard doesn't consider hosting vanilla servers to be an option, citing "tremendous operational challenges" as an obstacle despite internal enthusiasm for the idea. However, there might still be some hope for players looking for an experience closer to the original WoW:
If a tiny group of people with little to no resources could make a full fledged vanilla server with ease, why can't a multi billion dollar corporation?