First release premieres sometime in 2026 and is titled “Made in Abyss: Awakening Mystery”. Check out the ANN article for more information. Synopsis for the first season from AniList:
The “Abyss” is the last unexplored place in the world. Strange and wonderful creatures roam within, and it is full of precious relics that present humans can’t recreate. Those that dare to explore the depths are known as “Cave Raiders.” An orphan girl named Riko lives on the rim. Her dream is to become a Cave Raider like her mother and solve the mysteries of the cave system. One day, Riko starts exploring the caves and discovers a robot who resembles a human boy.
So is this new material or season 2 made into movies?
I believe this is new content. There isn’t too much more of the manga to adapt, not enough for a full season, so this is the outcome. I expect these will probably be more like OVAs than full feature films.
There might be enough for a movie if they already know the story will have an inflection point to end on coming. Anime seems to be working closely with the author so probably.