If Followed Footsteps and the enchanted creature leave the battlefield simultaneously (say via Upheaval or Akroma’s Vengence somehow cast in response to the triggered ability), then a token copy of the creature that was enchanted when it was last on the battlefield is created. If Followed Foosteps did not enchant a creature when last on the battlefield as it went to the graveyard as a state-based action when the enchanted creature left the battlefield in response to the trigger, then no copy will get created.