Ignoring my own personal hatred for Kingdom Hearts, it is extremely unlikely there will ever be a KH-themed crossover event in FFXIV - and that is for several reasons.
Firstly, the previous crossover events have all had some personal connection to Naoki Yoshida and/or FFXIV in general (the FFXIII event was the result of a private joke between Yoshi and FFXIII producer Motomu Toriyama at E3 in 2013 who, upon hearing Toriyama had added the FFXIV miqo'te starting armour and level 50 GLA/PLD Grand Company weapons for Lightning in Lightning Returns, Yoshi said he would "find some way to repay the compliment" by "having Lightning appear in FFXIV in some way" (paraphrased). Officially, the event was also to help promote Lightning Returns as well, which was launched around the time the crossover events ran.
Then there was the FFXI events which coincided with the eleventh anniversary of service for FFXI for the first event featuring Shantotto, and the official winding up of FFXI's storyline for the second event featuring Iroha - it was also a fond acknowledgement of the fact FFXIV is FFXI's symbolic and literal successor, as well as acknowledging Yoshi's predecessor as FFXIV's producer, Hiromichi Tanaka (who was FFXI's original producer as well). Finally, the Dragon Quest event (which few people seem to even remember) was celebrating Dragon Quest X's first anniversary of service, as well as a call back to Yoshi's previous game development project - he was formerly part of the DQX development team before he was promoted to producer of FFXIV after Tanaka's departure when FFXIV 1.0 failed.I'm not sure of the connection the Yo-Kai Watch event has to FFXIV's development team though, so, anything is possible I guess.
But a KH crossover event is still unlikely, if only for the reason KH is not exclusively owned by Square Enix, it is co-owned by Disney, and.. well... given Disney's rather.... heavy handed approach to protecting their IP rights, it would require a lot of legal wrangling to get a KH-themed crossover in FFXIV, the sort that would make intellectual property lawyers curl up in the foetal position in defeat whimpering softly to themselves.
And that is not even taking into account comments Yoshi made in an interview way back in 2013 before the game's launch that stated they would not run crossover events featuring characters who would not fit into the game's lore (or would negatively influence player perception of the game/s that character came from), whose stories are already complete, or who are dead in their respective games:
So although it is still a remote possibility, I think you would more likely see FFXIV 1.0 restored to operation than a KH crossover with FFXIV ARR. But may I be proven wrong though!Originally Posted by Gamerescape