Violet Evergarden: Band of Friendship is already in the cinema, but the tickets are not really cheap (12 euro), so the question is whether it is worth buying the tickets. Netflix participated in the show and aired it, so it's not so unlikely that the movie will air, I guess.
He is reportedly already listed on Netflix as a placeholder, but there's no date yet.
Netflix did NOT participate in the series. They only secured the exclusive streaming rights.
And 12 euro are normal for anime films.
Is listed, but no exact date is known.