I think we just need to view this as another level of the game but you need the right party!
First a Conjurer with Calm Skills followed by a Warrior with Refund Rage skills (though this may be ineffective due to adds aka Customer Service Agents debuffs); to draw out the adds you need a tank, preferably a Paladin, with Spirit Within Phone Skills, once the adds are drawn out then the Thaumaturge casts Forum Fire III to render the adds useless which should draw out the final boss Yoshi.
Casters should watch out for his "WeSincerelyApologize" mind debuff which will cause delay and lag spikes but his deadliest moves are the 601 and 90000 AoE quickly followed by a random choice of "World is full", "You are already logged in", or "Unable to complete version update" which will affect all parties members and cause the instance to reset. However, once defeated you will get Achievement Unlocked: Ultimate Zen Patience award and will be allowed to continue playing the original quest line.
So you see with the right party you can overcome this newest bonus level!