There was a "maze" type event datamined from the game at launch with a bunch of graphics referring to the "Kaleido Labyrinth" and "Kaleidoscape". A lot of people were expecting something similar to this for that event but it never materialized and seems to have eventually been replaced by the Mercurial Gauntlet we have now (Fafnir Roy III was originally in the Kaleido graphics and had voice files referring to it).

It sounds to me like they probably had to scrap it due to technical limitations or otherwise just not getting it to work properly, so I wouldn't get my hopes up for anything similar any time soon (though I really would like one as well...)