So, there's kind of a new Star Trek novelverse story, but also not?
Let me explain.
During the 2020 lockdown, Una McCormack started writing a third Cardassia Prime novel to conclude the storylines from The Crimson Shadow and Enigma Tales, called The End of This Day's Business. Well, given it was specwork and the novelverse was superseded by new on-screen material, it was obviously unpublishable in addition to not being completed before paying work came around. It was put on the shelf unless and until there was time and space for her to finish it off, though she has said some character and thematic elements of it were reflected in Second Self.
In what I'll choose to describe as a peculiar coincidence, a story called The End of This Day's Business which concludes the Cardassian plotlines from The Crimson Shadow and Enigma Tales, is being posted in installments on the Archive of Our Own on-line fan-fiction repository by a poster with the username Eleta_Preloc, with one chapter and two epilogues still remaining to be uploaded as I write this. Because of TrekLit's rules against posting story ideas and fan-fic, I won't link directly to The End of This Day's Business by Eleta_Preloc on an Archive of Our Own dot Org or posting a full-on review and discussion thread (unless maybe we make a general thread to talk about all the "lost" novels that were eventually posted on-line like Music of the Spheres and the original version of A Flag Full of Stars), but I knew everyone would be interested in this window into what might've been.