I must admit to a prejudice -- I'd gotten into the habit of thinking that standalone, during-the-series books had to be less significant and in-depth than books set after the series, with everything restrained by the reset button. I really should know better.
Revenant certainly showed me that, because it told a very effective story, a deep dive into Jadzia and Dax's earlier hosts, in a way we couldn't have gotten post-series for obvious reasons. It builds on the unresolved issues about Joran and the events of "Indiscretion" and tells a story that reveals a lot about Trill society and about Dax's past in particular.
I did have a couple of worldbuilding issues; for instance, the early chapters seemed to assume that capitalism was alive and well in the Federation, with Dax being very concerned about money and budgets. Also, the portrayal of the Caves of Mak'ala as being right underneath the Symbiosis Commission building seems to conflict with how
Discovery portrayed them in season 3, though I don't recall how "Indiscretion" portrayed them.
I don't recall
Worlds of DS9: Trill well enough to know if there are any major inconsistencies in the two books' portrayals of the Trill homeworld and culture. Normally that wouldn't matter, since different tie-ins have often presented incompatible extrapolations on such things. But the conceit of
Coda is that the novelverse is an alternate timeline to the canonical one, a conceit that only holds up if things that predate the timeline split, like the culture, history, and geography of a given planet, are consistent between the two timelines. Not that it really matters to me; I've spent most of my life accepting incompatible Trek tie-ins as simply different creative interpretations. But since the "alternate timeline" rationale has been put forward, I'm curious whether it actually holds up in practice.
It used to be fairly solid -- bookstores received stock on Mondays, and then you'd show up on Tuesday for new releases. A lot of places were very strict about not shelving the books early, though occasionally there would be a mistake. I guess the explosion of online sales over the last couple decades has made some of those models irrelevant but in my imagination the concept of New Release Tuesdays holds firm.
My lifetime experience as both a customer and occasional employee of bookstores is the opposite -- the norm, going back well beyond the last couple of decades, was that there was no firm release date and books were shelved whenever the bookstore employees happened to get around to unpacking the boxes they were in. As far as I can recall, I was never instructed to hold off on shelving a book before a certain date; the job was just to get as many books out of their boxes and onto the shelves as you could, to make room for the next shipment of books. As a customer, I would sometimes want to buy a book before it had made it from the back room to the shelves, in which case the clerks would often go back and find a copy for me, never telling me I had to wait until a certain day. I probably did the same for the customers when I was an employee too.
I've seen it said many times in this forum that strict release dates only apply to big-name book releases like the new Harry Potter (when that was a thing) or the new Stephen King novel or whatever, and that for most books, it just didn't matter.