Writer Doranna Durgin sez, "For eighteen months, publisher Fitzhenry & Whiteside has refused to honor the contract reversion clause for one of their fantasy titles; they have persistently demurred, ignored, and rebuffed attempts to discuss the situation, whether approached via agent, SFWA GriefCom, or directly. At this point, silence is their friend–but not in the interests of anyone else, including writers who are actively submitting YA works. The linked post presents a summary based on saved emails, the contract clause in question, and screenshot evidence."
Some context for non-writers out there: while creators in other fields (music, say) are typically required to assign their copyrights to their publishers/labels/studios, fiction writers have a much less oppressive arrangement with our publishers. We typically license our works to our publishers, and the publishers only get to keep those licensed rights for as long as the book is "in print." The definition of "in print" has evolved over the years, but typically it means, "the publisher has copies that it supplies to bookstores through its fulfillment system." The exact details of "in print" are spelled out in each book's contract.
According to her version of the story (a version corroborated by independent sources, like the Science Fiction Writers of America's Grievance Committee) Durgin's publisher is most certainly not keeping her book in print per the terms of their contract. The fact that they've demanded that Durgin buy back their leftover copies of book as a condition of holding up their end of the contract is without precedent — indeed, it's a breathtaking violation of publishing norms, the sort of thing you're more likely to encounter from ripoff vanity publishers and not a respected house like Fitz and Witz. Writer Beware indeed.
After another nudge—which included the reminder that the publisher could continue to sell warehoused copies in their usual fashion, as well as a reminder of the boilerplate changes–we were finally told: "This book is in stock, on sale on our website, it continues to sell albeit in lesser quantities. [my note: yes, a handful of copies a year] We have some 1,600 in stock with no reason to revert rights."
How about because it's a contractual obligation?
…Early the next day, I heard from the GriefCom chair that he had received a phone call, and that the unidentified caller took him to task in no uncertain terms–claiming harassment, declaring there would be no reversion on the title, and warning that she would "report" us to [prominent Canadian SF writer #1] and [prominent Canadian SF writer #2]—all before hanging up on him.