Not a movie. It's a cash grab and a disservice to the Kimetsu no Yaiba fan community.
They should have not released the last 2 episodes on Netflix, Crunchyroll or any streaming platforms, then it would have appealed to be a movie. Unfortunately 2/3 of the "movie" was a recap of the last portion of the recent season, then 1/3 is a prelude to the actual "training". If you would check out the IMDB synopsis of this movie, it says that:
"Tanjiro undergoes rigorous training with the Stone Hashira, Himejima, in his quest to become a Hashira. Meanwhile, Muzan continues to search for Nezuko and Ubuyashiki."
This is bullsh!t. This never happens, and was it not even remotely close to happening at all.
Cash Grab 10/10