The big news was announced at the end of Episode 26, the final episode of the anime.
Sotozaki Haruo has been confirmed to return as director for the movie, along with Matsushima Akira for character design and ufotable for animation.
Based on the manga by Gotouge Koyoharu, Kimetsu no Yaiba follows kindhearted charcoal seller Kamado Tanjirou, whose life changes forever when his family is attacked by demons, leaving only him and his sister alive. In order to return his sister (who is now a demon) to her former state and avenge his family, Tanjirou sets out on a dangerous journey.
(C) Gotouge Koyoharu / Shueisha, Aniplex, Ufotable