Who knows what will be announced this year in terms of new games in the KH series and whether it will be announced sometime this month or later this year.
I do expect the next new KH game (DDD v2; the KH game centered on Riku and Kairi) that is in development and coming sooner for the PS5 (or whichever console it's releasing) will likely come out around mid-late 2021 or 2022, perhaps the latter as it's the 20th anniversary of the first KH game and the KH franchise and going by the release pattern on how they release a new
Kingdom Hearts game, it's usually 1-2 or 2-3 years for a new KH game (depending of the KH title) to come out. The longest we had to wait for a new KH title was II.8 Final Chapter Prologue which came out 5 years after the release of Dream Drop Distance in 2012.
So I envision DDD V2 by late 2021/early 2022, and KHIV approx. 2023/2024.
Square Enix is still using the Unreal Engine 4, and they can still reuse the character models (e.g. Sora, Riku, Kairi, Donald, Goofy, Roxas, Ventus, Aqua, The Foretellers, Xigbar, etc..) and worlds (e.g. Twilight Town, Radiant Garden, Destiny Islands, Toy Box, Arendelle) from
Kingdom Hearts III for the next KH games without restarting from scratch again so development will move a lot faster than in previous KH titles. However, when it comes to the new Disney/Original worlds and characters they create, it may take them another year or two to develop, plus with the announcement of Unreal Engine 5, it will make the development cycle for the next KH games interesting.
Here's a breakdown for the development for the KH games:
- The first KH game started development started in the year 2000 and ended in late 2001/early 2002 (Jan./Feb. 2002) which means development lasted for 2 years. For Kingdom Hearts II, development started after the release of KH Final Mix in December 2002 and lasted until mid-late 2005 (2 1/2-3 years).
- Not sure how long development for Chain of Memories, Coded, and 358/2 Days took, but I think the former started sometime after the release of the first KH game and before KH2 entered Development.
- Development for Birth By Sleep started since 2005 and lasted until late 2009 (4 years), Dream Drop Distance started since early 2010 following the release of BBS and lasted until late 2011/early 2012 (1 1/2-2 years).
- Finally, Kingdom Hearts III had the most interesting development for a KH game, as development started since late 2012/early 2013 but due to a switch from Square's Luminous engine to the Unreal Engine 4 in October 2014, development for KH3 restarted under the new engine up until November 2018 (5-6 years of KH3 being in development (1-2 years under Luminous; 4.25 years under the Unreal Engine 4).
- Regarding the II.8 Final Chapter Prologue, I think development for that title started around the same time that KH3 switched into the Unreal Engine 4 (October 2014), even the Graphics from 0.2 Birth By Sleep seems to suggest it was the first KH title that the team was testing on and the graphics for this game looked uncanny when compared to the Unreal Engine graphics of the X Back Cover movie and Kingdom Hearts III.
Also, most new
Kingdom Hearts games usually are announced at the Tokyo Game Show (e.g.
Kingdom Hearts II,
Coded, 358/2 Days, BBS, the HD Collections and
II.8 Final Chapter Prologue), but there were some exceptions to this, such as
Dream Drop Distance (previously announced as KH: 3D) and
Kingdom Hearts III which were announced at E3 2010 and E3 2013 respectively.
But with E3 and TGS canceled due to COVID-19, Nomura and Square Enix need to make some sort of announcement sometime this month or later this year, unless if they want to continue focusing on highlighting Union χ and Dark Road instead.