Kingdom Hearts 3 director, Tetsuya Nomura, has said that switching between the English and Japanese voiceovers in the game is proving difficult to support.
Nomura mentioned the difficulties in an interview with Weekly Famitsu, via Gematsu, saying that the differences in lip syncing to the audio is causing the issue. It’s not clear from the interview whether it’s something the studio is continuing to look into solving.
Nomura also touched on the size of the game as a whole, saying that some in-engine cutscenes are being turned into pre-rendered movies to reduce load times.
Source: IGN.com Kingdom Hearts 3: Switching Between English and Japanese Voiceover 'Difficult' Right Now