There's no clear indication that it's a sequel. It might just be a different take on the Firewatch concept, exploring different aspects of the setting or characters in a visual novel format rather than as a traditional game sequel.
The full story in Arknights is complex and engaging. It involves the struggle between different factions in a post - apocalyptic world filled with a deadly disease called Oripathy. There are various characters, each with their own backstories, motives, and abilities. The story unfolds as the player - led Rhodes Island organization tries to find a cure for Oripathy and deal with the political and military threats around them.
Well, a 'Firewatch Visual Novel' could be centered around the experiences of the firewatchers. It may include elements like their daily routines, the isolation they feel, and any strange events they encounter in the woods. It might also explore the beautiful yet somewhat eerie landscapes that are characteristic of the Firewatch setting.
The story of Firewatch is about Henry's experience in the forest and his relationship with Delilah. The ending is complex and has different meanings for different players. It might involve choices that have consequences and a sense of closure or ambiguity, depending on your perspective.