The Warcraft storyline has come a long way since Orcs and Humans. Bobbyjeh of Aman'Thul asked how Blizzard maintains their "seemingly endless lore and story arc. Nethaera responded that the company has a Historian on staff as well as an expanding department dedicated to lore. They cover all three of the major Blizzard universes. They help to keep continuity in the game and keeps things interesting for our resident Lore Nerd.
While I was doing the quest chain for my Swift Flight Form, I wondered to myself. What does someone who's been asleep for so long know about Outland? I've often wondered how it is that new Draenei characters all crashed "one month ago." As some pointed out, there has been some discontinuity in the Warcraft Universe. But Blizzard does a pretty good job of keeping their story straight. No stranger than C3PO saying, "Thank the maker," when technically, Darth Vader is the maker. We accept these plot holes and move on.