What are Private Auras?
Private auras were added in Patch 10.1 and Blizzard's first attempt at dealing with computational addons. Addons were not able to track certain aspects of Private Auras, preventing them from directly making computational assignments. Players quickly found workarounds, including a macro that would inform addons they have the a debuff. Once this happened, Private Auras were just handled in the same way, but were more frustrating due to additional inputs that needed to happen and this was frustrating to many players. Blizzard acknowledged that Private Auras were frustrating and were not improving the player experience and moving into the War Within, they used them in a different way that was relatively non-intrusive.
Private Auras Are So Back
The addon changes in Midnight prevent computational addons from automatically doing assignments, so private auras should theoretically have no reason to exist anymore, especially after Blizzard determined that they were frustrating for players. Despite this, in the Midnight Pre-Patch and Midnight Season 1, there are over 700 new private auras that have been added recently.
There are over 300 new private auras for War Within Season 3 in the Midnight Pre-Patch, with over 400 new private auras for Midnight Season 1.
This includes almost every debuff in the current raid and dungeon pool, and for the upcoming Season 1 raids and dungeons in Midnight. Even if the debuff is a simple DoT, it has been made into a Private Aura.
Why are there so many new Private Auras?
Addon Functionality Workaround
The reason that Private Auras may have been added is for players to be able to work around some of the addon restrictions. Due to the new secret values system, addons and players are not able to add sounds or additional notifications when they get a debuff as addons have no idea what debuffs you have. If you're standing in fire, or receive a targeted DoT effect, you're getting a debuff and this may be hard to see in your debuff list. Many players have asked for a whitelist / blacklist system to be able to filter out debuffs that they don't want to see such as Challenger's Burden and Sated. With a curated list of Private Auras for boss mechanics, this would at minimum filter out non-important debuffs, with all the important debuffs being curated by Blizzard. And that's the important thing to remember if this is intended, Blizzard has to curate the list of Private Auras, and they could just as easily not provide the needed information or Private Auras in a future tier, or even in a hotfix.
With Private Auras, players will be able to create a Private Aura box, allowing them to resize and move where Private Auras show on their screen. This could be really useful for curated boss mechanics.
Sounds May Be Returning
There is one more thing that players can and have done with Private Auras -- adding custom sounds to specific spell IDs. In other words, players should theoretically be able to add specific sounds to specific debuffs.
The word here is theoretically because as of right now the functionality is currently broken, and it's unclear whether or not this workaround is intended or not. On one hand, why else would Blizzard be adding so many Private Auras. On the other hand, this seems to go against some of their addon goals.
If this works how Private Auras used to function, addons could be developed to attached customs sounds to specific Private Auras. This is reliant on Blizzard marking the debuff you're looking for as a Private Aura, of course:
Pop an Air Horn on an important debuff that is super important.
Make a custom announcement reminder people what to do with certain debuffs.
Remind yourself to use a Defensive if you get a deadly DoT effect.
... and so on...
Many addons including Big Wigs, DBM, Northern Sky Raid Tools have or will likely add functionality to support this. This also means that addons such as GTFO could also survive and have a purpose in Midnight.
We'll have to see if this functionality makes it into the Midnight Pre-Patch or Midnight Season 1.
