Mythic L'ura
After Liquid defeated Belo'ren, they debuted two addons that took the community by storm. One of the addons was a memory game helper which Echo has now developed a similar addon for, while the other was an aid for interrupts.
Terminate
On Mythic difficulty, the Terminate is a 1.5 second cast, that needs to be interrupted 5 times sequentially. There are three of these casters, and if a single cast goes off, it's almost certainly a wipe. There are two difficulties with this mechanic: the first is targeting the correct Matrix as they are constantly rotating, and the second is kicking the correct number cast. Liquid originally showed up to L'ura attaching a unique identifier to the nameplate, something like Theta A, or Theta B to help raiders know which one to target.
The First Hotfix
This hotfix came very quickly after Liquid showed off this first addon, and it's pretty likely that Blizzard did not like this initial implementation. The original way this addon worked was likely GUID related and the hotfix targeted that specifically, but in the process also added the Termination Matrix adds to the boss frames.
This has lead to a brand new addon targeting system -- using boss IDs. Macros can specifically target boss frames without having to change targets. Players can use , , or to specifically target a specific Termination Matrix. You don't actually need to know which Matrix is which as the game just does it for you noow. There's some complications about shuffling when one dies, but it's mostly handled by itself now.
Interrupt Anchors from the Dead
Now that targeting was sorted using macros and Blizzard adding the adds to the boss frames, the last thing that could be improved was counting. The number of stacks on the Termination Matrix count down from 5, which should give you an idea of what number kick you're on, but boss frames are to the side and out of the way usually. This lead to the revival of an old friend, the Interrupt Anchors Weakaura.
These Weakauras were very common place in expansions before Midnight and do one thing very well: track the number of kicks and casts that have occurred. These addons also allow you to play a sound when it's your turn to kick and all of these features sound perfect for this mechanic.
Interrupt Anchors No More
When Liquid starting streaming this morning, the Orange Box attached to nameplates was gone. Nothing public has been said about why that portion of the addon was removed, but interestingly, the other portions of the addon remain. Now, raiders can simply just ignore any visual cues, and press their interrupt button when they hear an audio alert, such as an Air Horn.
The addon seems to functionally work exactly the same, except the visual portion of the addon is gone. It's possible that they didn't need it anymore, but an interesting development occurred later in the day.
WoWUI Discord Messages
Later in the day, some interesting messages were posting in the WoWUI Discord.
WoWUI Discordhypothetically if the restrictions on UnitIsUnit in 12.0.5 were to be surprise hotfixed in, who would complain?
This was shortly followed by:
WoWUI DiscordThis is no longer a hypothetical, please make preparations over the weekend
Liquid's addon was almost certainly using UnitIsUnit to attach the interrupt anchor onto the correct nameplate, and if Blizzard is hotfixing this in, interrupt anchors on nameplates will be broken. If we continue along this line of speculation, it's entirely possible that Blizzard did not like the visual aspect of the addon, but are okay with the audio alert, and are making a quick move to hotfix in more addon restrictions to prevent the visual portion. If the top guilds were told not to do this, other guilds will likely try to copy this functionality especially since there has been no public statement.
UnitIsUnit is Dying
What will change with this? It's hard to have a complete list, but here are some of the notable examples:
Interrupt Anchors on Nameplates should be dead.
Glows for Light/Void Dive on Belo'ren will no longer work.
Conclusion
It's unclear how Blizzard wanted this mechanic was supposed to be solved initially. 1.5 seconds is not a lot of time for the first cast, and with no boss identifier, players would have to quickly determine on spawn which of the marks is theirs, mark it and do the first kick. That doesn't feel like enough time to consistently do that.
Blizzard has talked about affordance before and the affordance on this mechanic seems way off -- a short cast, no easy way to separate matrices from each other, all while having to do top DPS and dodge deadly glaives. And it's very clear what happens when affordance on a mechanic is off; players will find any way to take some of the cognitive load off of themselves. If the first cast was longer, and then got sequentially shorter, if the matrices were colored differently or had unique efefcts, if the boss was immune during this phase like Heroic, or if the glaives didn't hit so hard or wipe you, all of those would help, but right now I think addons are here to stay with the current tuning of this mechanic, so I hope you can react quickly to an audio queue if you plan on doing this boss.
The Memory Game
The Memory game is very different on Mythic difficulty. Players get separated into three different phases, and can only see a portion of notes that are needed to complete the pattern. Each realm then gets their own set of 5 symbols and all phases need to form the correct pattern to not wipe.
When Liquid originally debuted this addon, the community reacted very strongly to it. Considering the addon still exists, it's likely that Blizzard isn't doing anything about it at this time. Not much has changed, other than one improvement.
Sound Cues
Players can't see all the notes in each phase, and so there are gaps in the pattern. Players might have trouble knowing if their symbol was second or third if a person before them called it late. Liquid has added an audio counter letting players know the cadence of the note spawns so that players can more easily tell what number each note is.

