Twitter integration, a feature added in Warlords of Draenor to allow players to easily share screenshots, achievements, and rare loot drops directly from World of Warcraft to Twitter, will be removed from the game over the next few days, presumably the result of Twitter API changes over the last week, which will begin charging third party users a monthly fee for access.
Over the next two days, we will update World of Warcraft® to remove the integrated Twitter® posting feature.