In addition to the effect of its equip ability, Grafted Exoskeleton becomes unattached from the creature it's equipping if a spell or ability (such as Fulgent Distraction) causes it to become unattached, if Grafted Exoskeleton leaves the battlefield, if the equipped creature ceases to be a creature, or if Grafted Exoskeleton ceases to be an Equipment. (It also becomes unattached if the equipped creature leaves the battlefield, but the triggered ability won't do anything in that case.)