Rather, when Star Trek Online was created in 2009-10, its creators deliberately chose to contradict the direction the novels had already been going in for years. It borrowed some ideas and characters from the novels, like Titan and President Bacco, but it disregarded most of the DS9 post-finale series, the events of Destiny and the surrounding books, the novels' prior portrayals of races like Species 8472, and so on. STO chose to be a separate continuity from the start, and it and the novels have both been charting their own independent courses.
Fair enough. I wasn't entirely sure where the difference in courses had started. Do kinda note that they do seem to take an inordinate delight in doing everything in the reverse of how you seem to flesh out a lot of "seldom seen" species, ranging from 8472 in Places of Exile, to the difference between the "Elachi" and your portrayal of the aliens in A Choice of Futures. (Plus the crystalline entity and some other things I'm sure I'm forgetting)
While I can see some of it being necessary from the standpoint of making a video game (and I enjoyed it for a long while) it's disappointing because a lot of the Star Trekiness is sacrificed on the altar of combat mechanics. I get the sense they'll be doing something similar with the Voth soon.