I think Square Enix really wants to hammer the idea home to you that yes, Kingdom Hearts 3 does exist and yes, Kingdom Hearts 3 will be released on January 29, 2019. We had new trailers from the Xbox E3 event, from Sony's E3 event, and you better believe that there was one at Square Enix's own E3 event.

Let's start with the Xbox one that showcases some realistic Pirates of the Caribbean people with... Goofy.
This action-packed trailer reveals that Sora, Donald, and Goofy will revisit Pirates of the Caribbean world with KINGDOM HEARTS III!
Check out the new combat styles, underwater battles, and new Keyblade transformations as our heroes continue their perilous adventure.

There was also a trailer for the Frozen portion of Kingdom Hearts 3. You know, the whole "let it go" stuff? Yeah, that. There was also just a kind of generic trailer shown off during Square's conference as well. Plus there was at least one gameplay interview that I've seen. I'm sure there are more out there but I figure four videos for one game would be a pretty good starting point for you. There's also a bunch of new screenshots that Square Enix has shared.

Kingdom Hearts 3 is slated to be released on January 29 for the Xbox One and PlayStation 4.