The project is a film due out in 2021 that will be called Sword Art Online the Movie -Progressive- Aria of a Starless Night.
Sword Art Online: Progressive is a new version of the Sword Art Online tale that starts at the beginning of Kirito and Asuna’s epic adventure–on the very first level of the deadly world of Aincrad!
The film has Ayako Kawano directing it with Kento Toya handling the character designs for it.
You can see more details for locations at the official film site as it becomes available.