The Kingdom Hearts series was once seen as a crossover between the Disney animated franchises and the Final Fantasy video games. There has been a notable drop-off in non-KH characters in Kingdom Hearts over the years, with Kingdom Hearts 3 barely having Final Fantasy Characters at all. Kingdom Hearts creator Tetsuya Nomura recently discussed the reason for the absence of Final Fantasy characters in Kingdom Hearts and what it means for the upcoming Kingdom Hearts 4.
The first entry in the Kingdom Hearts series was heavily promoted on the fact that it had characters and settings from popular Disney films and Final Fantasy games. This was in the era before Square Enix started countless Final Fantasy crossover mobile titles, so the idea of seeing Cloud and Squall in the same game was still new. The fact that Kingdom Hearts featured characters from FF7, FF8, and FF10 was seen as a huge draw to JRPG fans, while the Disney content appealed to the more mainstream audience. This isn't to say that Kingdom Hearts wasn't without controversy, as a lot of Final Fantasy fans complained about Sephiroth being voiced by Lance Bass from NSYNC, but the response to the game was positive, and it led to the creation of one of Square Enix's most popular franchises.
Kingdom Hearts 4 was announced at 20th anniversary celebrations for the franchise, with a trailer that showed Sora in Quadratum. The trailer featured Sora, Donald, Goofy, and a character who is likely Hades from Hercules, but there weren't any Final Fantasy characters to be seen. Kingdom Hearts creator Tetsuya Nomura recently spoke to Game Informer about the history of the series, where he explained the original reason for the Final Fantasy crossover content and what it means for Kingdom Hearts 4.
Final Fantasy Was Used Due To Lack Of OG Kingdom Hearts Characters
According to Nomura, the Final Fantasy characters were used in Kingdom Hearts to help establish the new Kingdom Hearts characters to the audience, as they were brand new to the players, and were novices in their own setting. As time went on, the series added more and more original Kingdom Hearts characters and the audience wanted a resolution to their storylines, rather than the Final Fantasy characters in Kingdom Hearts. It became harder and harder to find time to include the Final Fantasy characters, which is why their screen time was reduced. Nomura said that fans want to see more Final Fantasy characters, but they're still trying to work out a balance between them and the Kingdom Hearts characters, which is still being worked out for Kingdom Hearts 4.
The Final Fantasy characters helped propel the Kingdom Hearts series to mainstream status in the old days, and it would be a shame to see them sidelined in future entries in the series. The series should also give cameos to other Square Enix franchises, as was the case with The World Ends With You cast in Kingdom Hearts 2.8. Kingdom Hearts 4 has the chance to explore other Disney franchises, such as the MCU, and the recent trailer hinted at Star Wars content in Kingdom Hearts, but Square Enix should make an effort to include Final Fantasy characters, as fans still love these alternate Kingdom Hearts iterations of famous heroes and villains.
Source: Game Informer