As detailed by Blizzard in a recent blog post, the procedure for attuning that allows players to participate in the raids to begin on September 15 not quick nor simple. Just like it was with the first Burning Crusade launched in 2007 the process of getting tuned is the result of a lengthy process. First, players need to be able to acquire various keys, unlocking various dungeons and raids, then finish those dungeons, raids. After that, players must complete many more dungeons at more challenging difficulty. There are also long quest chains that often need up to five players to complete.
The whole process can take upwards of a dozen hours or more to complete, and it's one of the main reasons Burning Crusade, as groundbreaking as it was back then it's now famously associated with intricate attunement charts, like ones below.
I found the original TBC Raid Attunement Chart on my old laptop WOW!
This lengthy attunement journey not only served as a barrier for players to conquer however, it also became an issue on the eyes of guilds hoping to recruit new members in later stages to the games. Because a large number of new or returning players were unlikely to have been through the attunement buy WoTLK Gold requirements in order to fill slots in their rosters would frequently turn to poaching players from other guilds.