During the last few days, an interesting preview about Kingdom Hearts III has been published by website Geek.com, and among the other things the preview claimed that the game’s campaign would’ve featured main content for 40-50 hours and secondary stuff for a maximum of 80 hours.
Since the publishing of the preview, anyway, Square Enix hasn’t offered an official comment about the length of the title itself, and didn’t even shared a statement when asked about that by IGN.com.
On top of that, Geek.com has edited the article to reflect the fact that the developer and publisher from Japan hasn’t commented about that in any official circumstance, and that basically the preview made a guess based on previous interviews of the core staff.
Indeed, Tetsuya Nomura, series director, has said in the past that Kingdom Hearts III would’ve been the biggest game in the franchise, so that’s possible that the main campaign alone could be so long to span over the course of 40-50 hours.
Kingdom Hearts III is releasing on January 29, 2019, so we’re very close to unravel this mystery ourselves. We definitely don’t expect any official, clearer statement from Square Enix on the topic.