Fact:
5/22/2015
Blizzard announces no flight ever again.
6/10/2015
Blizzard changes mind - will return flight
http://www.polygon.com/2015/6/10/8761289/world-of-warcraft-warlords-of-draenor-flying-update-mmo-pc-mac-blizzard; Dev Water Cooler announcement on Blizzard website reveals Pathfinder Achievement without details or release date.
During that 19 day interval, servers emptied, guilds folded, long-time veteran players left the game in droves. For the first time, Blizzard employees solicited, online, cancellation reasons from departing players. These forums were flooded with over 150,000 posts, hundreds of threads in protest.
That’s 19 days where nothing else happened.