It's unknown, but it's likely it will not be the original FFXI event which indeed rewarded a Wind Up Shantotto minion (that event was to coinicide with FFXI's eleventh anniversary of service and tied in with the FFXI A Shantotto Ascension mini expansion).

Most likely this will instead be the second FFXI event featuring Iroha that is connected to the FFXI Rhapsodies of Vana'diel missions that officially completed FFXI's storyline - the reward for that event is Iroha's Eastern-themed armour (head, body, feet, legs and hands).

In fact, given the Far Eastern connections of Stormblood, it's almost guaranteed to be the Iroha event, meaning if you missed out on the Shantotto minion, you're out of luck sadly.