Premieres sometime in 2025. The new PV is here. Check out the ANN article for additional information. Synopsis from AniList:

The Obinata Fireworks Shop factory is getting prepared for an administrative action for confiscation tomorrow. It has been six years since Keitaro has been holed up in a closed-down factory creating fireworks by himself, chasing after an illusion of his father who vanished. It is a story about three young people who overcome the extreme weather conditions, disasters and environmental problems imposed on them and establish their own identities.