[Interview with Studio BONES co-founder Toshihiro Kawamoto] “Studio F is currently working on a project that will be announced over the next year… we’re currently fully booked until 2026 and even 2027. We could get into trouble if a title becomes so successful that a sequel is absolutely necessary.”
https://www.reddit.com/r/anime/comments/1fuwj4a/interview_with_studio_bones_cofounder_toshihiro/