I didn't hear about this until recently, but as of June 2024, Endor Productions announced it will close and "will focus exclusively on the completion of current productions". I'm not familiar with the books, but I thought S4 covered the last book (with the author not currently talking about publishing more). Neither of these rule out a different production company/network picking the show up or original material taking the place of a book adaption in possible future seasons, but I haven't heard of anyone specifically talking about a rescue.