Phase 2 has now been out for one week and many players have been reporting threat issues during the final phase of the Kael'thas encounter in Tempest Keep, one of the two new raids added with the recent update.
In a blue post on the World of Warcraft Forums, Community Manager Kaivax said that it is a known bug and the team has been working on a fix over the past few weeks.
The issue should be resolved soon but it will likely require realm restarts for the update to go live
This issue is one of many that launched with the release of the first major content update of the Burning Crusade Classic last week.
Latest Updates: Blizzard has hotfixed the threat drop issue that was affecting many different mobs today, with the fix likely already in the game.
Blizzard Provide An Update On Kael'Thas Threat Issues In The Burning Crusade Classic
Many players were quick to criticize Blizzard after the comments were made as the patch had only been out for a week when they said it has been under investigation for several weeks.
Knowing this, they still pushed the patch out that was filled with bugs not only in the new raids but also the new Factions players were excited to begin grinding new reputation with.
In a Hotfix today, Blizzard has fixed issues around both the Ogri'la and Sha'tari daily quests, and the new Phase 2 raid bosses who were missing items on their loot tables.
While many players are upset at the bug going through to launch, many are disappointed it took over a week of the game being live for Blizzard to address the issues publically.
Players should expect to see this issue resolved before the weekend.