Via the WoWUIdev Discord, they are currently okay with this workaround and the article has been updated.
Color-Coding Enemy Nameplates
One requested feature from some players is the ability to color-code enemy nameplates according to mob type. Many players use color-coded enemy nameplates to easily identify dangerous mobs, especially casters and priority targets, in The War Within. Color-coding nameplates according to enemy mobs is a massive advantage in keys that many players use.
With the disarmanent of addons on the Midnight Beta, many players have been asking for color-coding nameplates to return over the last couple months. Now, players have found a near-perfect way of separating mob type based on criteria that is provided to addons:
Enemy Level
Elite Status
Casting Status
Using these criteria, UI developers have discovered that you can color nameplates with high accuracy by looking at these criteria in certain ways:
Level 92: Boss
Level 91 & Elite: Lieutenant
Level 90 & Elite: Melee Mob
Level 90 & Elite & Has is Flagged as a "Paladin": Caster Mob
Level 90 & Elite & Has Interruptable Cast:
The nameplate would only flag to a caster on the first interruptable cast.
This is only possible with a special script and is not available out of the box.
You can see these colors in the screenshot below using this criteria.
This was made using Platynator and the default customization options and it works relatively well!
As mentioned above, there is an additional script and code that can be added to Plater and Platynator that allows real casters to swap their nameplate color the moment they cast a spell, but that it not available out of the box.
Blizzard is Allowing This
One of the questions that many players have been asking is "Will Blizzard Break This?" According, to their previously stated addon philosophy, you may think that Blizzard would not allow this, but according to the WoWUIDev discord, Blizzard is tentatively allowing this.
3. Simplifying enemy names (e.g. "Healer"), cast names ("Frontal"), or colorizing unit nameplates based on priority
Reasoning: While this functionality may seem somewhat benign at first, it has played an important part in reducing the challenge level in end-game content over the last several years, particularly in M+. For most of WoW's history, learning which enemies were the highest priority or what to do when a certain spell is being cast has required knowledge, built up through practice and research. But when addons are able to call out exactly which enemies to kill first, which casts to interrupt and which enemies to run away from, that knowledge is no longer necessary. With that knowledge and mastery no longer required, we must compensate through other means in order to maintain a satisfying level of challenge for players. Larger packs of enemies become the norm, as do shorter cast times on lethal spells. Essentially, we are forced to replace mastery and knowledge gained through time with twitch gameplay that punishes players who aren't using addons and/or have slower reaction times. We recognize that our current naming approach does not always provide enough clarity, especially with longer creature or cast names, so we are also working on ways to address this on the design side for Midnight.
APIs Affected: APIs that allow addons to identify specific enemies and enemy spellcasts are the primary ones that need to be locked down to prevent this behavior.
This functionality seems to be the type of thing thing that Blizzard would be looking to break with nameplates, so it's odd that they're not, as Blizzard sees the knowledge of which enemies are the highest priority or which mobs are casters as being part of the challenge of the game. Color-coding functionality is also not part of the in-game UI, and so this theoretically breaks the rule of no competitive advantage from addons.
