Why is the New Yorker publishing a story by F. Scott Fitzgerald, and why was it never published before?

This week the New Yorker publishes an previously unpublished short story by F. Scott Fitzgerald, The I.O.U., from ca 1920, and notes that it is part of a forthcoming publication of unpublished Fitzgerald stories. This publication raises the question(s): Why was it never published?, and, Why publish it now? As we know, Fitzgerald was a professional, which is to say commercial, writer. He of course had a commitment to the highest standards of artistic ambition, and his best works are without question some of the finest examples of American literary fiction. But he wrote to earn a living; his were the days before sinecure positions on university faculties and genius grants - so he wrote stories for publication, that is, for $. And in his day there was a huge market for literary fiction in the many weeklies and quarterlies. So as to The I.O.U., did he hold it back because it failed to meet his standard for publication? Or was it rejected by a # of magazines? Or did it just slip through the cracks - that is, he was maybe still working on it and revising it and never in his view completed the story. I'm leaning toward the latter, as from my recollection there are a # of mediocre stories in his complete published opus - he often needed the $ and publications then as now were highly influenced by the reputation of the authors when decided on what to publish, or not. As is the New Yorker today, of course. Clearly this story is middle-weight Fitzgerald at best; it's the tale of a successful publisher who publishes what he hopes will be a best seller by a psychic who claims to have had years of communication with his son who died in the World War; the publication scheme unravels, however, when the publisher learns that the son is alive and is livid about his portrayal in the book. I'm guessing this story may have been a a play on some successful publication of its era; today, it feels flat and dated. The strength is the first-person voice that FSF establishes, wry and funny and frank about his striving to make a buck; it's a tone that Woody Allan has emulated it some of his humor pieces for the NYer. The weakness, however, is the preposterous nature of the story: the idea that this book would be such a success, that the publisher would be shocked to learn that it's a hoax, etc. If I were able to give FSF advice on this piece (ha), I'd say it would work a lot better if the publication were something that the publisher could have and would have truly believed in: something like the Howard Hughes hoax biography of more recent years or one of the fake memoirs by a teenage gang member or a bipolar novelist that come up from time to time (a recent magazine piece examined this topic).