The official Violet Evergarden Twitter account (See below) has confirmed that there's a new anime project in development following the conclusion of the anime's 13th and final episode. Previously, it was confirmed that an OVA would be released on July 4th with the anime's final Blu-ray and DVD volume.
Some fans think the announcement pertains to the OVA while others insist that the announcement confirms that there's another season in the works.
There's also the wording of the Tweet, which states that the new project is a "completely new work," an indication that it will expand upon the award-winning light novel series written by Kana Akatsuki and illustrated by Akiko Takase.
The confirming Tweet comes after March saw the packaging for the Violet Evergarden Gaiden (side story) light novel reveal that a "new project was in progress" so there's a logical argument to be made that the new project will tackle the side story.
The series was simulcast on Netflix worldwide on January 11, except in the U.S. and Austrailia where it just began airing on April 5.
VIOLET EVERGARDEN SYNOPSIS
The Great War finally came to an end after four long years of conflict; fractured in two, the continent of Telesis slowly began to flourish once again. Caught up in the bloodshed was Violet Evergarden, a young girl raised for the sole purpose of decimating enemy lines. Hospitalized and maimed in a bloody skirmish during the War's final leg, she was left with only words from the person she held dearest, but with no understanding of their meaning.
Recovering from her wounds, Violet starts a new life working at CH Postal Services after a falling out with her new intended guardian family. There, she witnesses by pure chance the work of an "Auto Memory Doll," amanuenses that transcribe people's thoughts and feelings into words on paper. Moved by the notion, Violet begins work as an Auto Memory Doll, a trade that will take her on an adventure, one that will reshape the lives of her clients and hopefully lead to self-discovery.