i know that it's impossible to create a true AI, i'm not stupid at this point, however it's not true that it's not possible to give replayability to an raid.

let's take a boss fight, we all know that a boss use a pool of skill already etablish (even if in FF14 it's based by the % of the life of the boss on many fight) for the need of the example, let's say he can use 5 skill max, the 4 first skill are always the same, the last one change with each week, each week for each raid, it will use one skill taken from a pool of 3-5 skill designed for this fight.
indeed it will ask more time for create content... but in this way, each week the fight will change a bit without fall into full random or stuff totally idiot.

it's possible to do far more, they simply need to free themself from WoW shadow!