According to Blizzard in a blog post, the process of attuning for being able to take part in the raids WoTLK Gold to be added on September 15 is not simple or quick. Similar to the way it was when the first Burning Crusade launched in 2007 the process of getting tuned is an extensive process that requires multiple steps. The first step is to obtain various keys to unlock different dungeons and raids. They after which they must complete the dungeons and raids, then finish additional dungeons with more difficult difficulty. There are also long quests that typically require up to five players to complete.
The entire process can take up to a dozen hours or more to complete this is one of the main reasons Burning Crusade, as groundbreaking as it was in its time was, is now infamously associated with complicated attunement charts such as that below.
I found the older TBC Raid Attunement Chart on my old laptop from Wow
The lengthy attunement procedure not only served as a hurdle that players had to get over and overcome, but it also proved to be an issue on the sides of guilds trying to attract new members in later phases in the process. Since a lot of new or returning players had not completed the attunement process and guilds that were desperate to fill vacancies on their rosters would frequently turn to poaching players of other guilds.
With all the online guides and sources available today players are better equipped for the game's attunements of 2021 than they were back in 2007. A lot of the quests that go along with the process could be initiated prior to reaching the level WOW WoTLK Classic Gold mark which means that many of the gamers who are the most dedicated have completed the required steps before the launch of the raids within two weeks.