Patrick Rothfuss has confirmed that his Kingkiller Chronicle trilogy is merely the "prologue" to another story, confusing a lot of people in the process.
Patrick Rothfuss released the first book in the trilogy, The Name of the Wind, back in 2007 with a lot of pre-publicity about how the trilogy was already complete and also with the intimation that the trilogy was merely the start of a larger story. After all, The Name of the Wind opens with a present-day storyline in which the world is clearly in chaos and darkness, and then the bulk of the trilogy unfolds in flashback and explains how events led to that impasse. Logically, unless Rothfuss was planning to end the series with "and everything sucks now, kthxbai", the story was going to continue in a sequel series which addresses the problems set up in the first few books.
However, Rothfuss has spent the decade or so since then refuting the idea of there being a further series or sequel. As the gaps between books grew longer (the second volume, The Wise Man's Fear, was released in 2011 and the third volume, The Doors of Stone, is still to be published), he has repeatedly played down suggestions that there are more books coming.
Why he broke his silence now is unclear, although there's been some significant news recently. There's both a movie trilogy based directly on the books in the planning stages, with Lin-Manuel Miranda (Hamilton) producing and Sam Raimi (the Spider-Man trilogy, the Evil Dead series) in talks to direct, and a prequel television series focusing on Kvothe's parents in development at Showtime. Rothfuss has also spoken about the book a bit more (after several years of avoiding it), indicating it will be shorter than The Wise Man's Fear and that writing it is uncomfortably like "having sex in public". There is, however, still no indication of when the book will be done.
So now we know what we only thought we knew in 2007. The circle is complete.