Below is a post from Prathun, We've changed how Mitigation of the Mighty buffs and stats are applied to bosses so that they are no longer applied when it's 5 era years after the content was introduced. So... Original EQ bosses stop using MotM once Gates of Discord has unlocked. Kunark bosses stop using MotM once Dragons of Norrath has unlocked. Velious bosses stop using MotM once Prophecy of Ro has unlocked. Luclin bosses stop using MotM once The Buried Sea has unlocked. Planes of Power bosses stop using MotM once Seeds of Destruction has unlocked. This coincides to when Fabled activate, so it should not be possible to get a boss that is both Fabled and has MotM. This should go out with the next full update.
