Disney and Marvel have revealed that they will be hosting a dedicated Gaming showcase on September 9th, 2022, at 1 PM PT/ 4 PM ET.
Currently, aside from the confirmation of "new content from Disney & Pixar Games, Marvel Games, Lucasfilm Games, and 20th Century Games," Disney Dreamlight Valley, Marvel’s Midnight Suns, LEGO Star Wars: The Skywalker Saga, and an unannounced "Marvel ensemble game from Skydance New Media" are stated to receive news.
There is no mention of Kingdom Hearts appearing. Still, there is certainly a chance it could, especially when recalling the franchise's previous showings at the D23 event umbrella, such as 2015 and 2017. Further, with this year being the series' 20th Anniversary, and with Kingdom Hearts IV and Missing-Link on the way, some semblances of acknowledgment could be made.
Of course, don't go into the event with presumptions, but simply keep an open mind to possibilities.
Links for viewing this upcoming event can be accessed via the official D23 website.