Demon Slayer the Movie: Mugen Train is in US theaters April 22-29 subbed and dubbed. The official release date is April 23. Maybe the theaters decided to release it a day early. :
Why is Demon Slayer so popular? : r/anime
Demon Slayer: Kimetsu no Yaiba' 3rd Anniversary Visual : r/anime
Demon Slayer: Kimetsu no Yaiba" Season 2 Visual : r/anime
Kimetsu no Yaiba The Movie: Mugen Train" is coming to theaters in the USA and Canada in 2021 : r/Animedubs