I think the main problem is SE overdoing it. They dont need to add mecanisms or rewrite the whole fight to fit the various players. They dont need to set name to different difficulties of it.(story,normal,savage)

They just need to scale the boss and mobs level and lets the players set their own difficulty. That would also give them more time since they wont need to recreate whole fight.

That system already exist in the game, its in "battleleves"