IMO, ASD was used to split the current 24th century TrekLit into 3 main branches: one focusing on Voyager and the Full Circle mission / fleet, one on Titan (StF was very much a Titan novel IMO, and less a TP one), and the third (or actually the "first") focusing on the Alpha Quadrant using the TNG cast (notice the flow from Losing the Peace, through Paths of Disharmony and The Struggle Within, to the recent duology), Aventine crew, Bacco administration and the (now-"reunited") DS9 cast.
I don't know why you're attributing all that to A Singular Destiny
alone. It was just one piece of the puzzle. After Destiny
, the editors at the time (Marco Palmieri and Margaret Clark) assembled a team of authors including Kirsten Beyer, Keith R.A. DeCandido, William Leisner, and myself to do a project that we informally referred to as "Cleaning Up Mack's Mess." The four of us worked on our books -- respectively, Full Circle, A Singular Destiny, Losing the Peace
, and Over a Torrent Sea
-- more or less simultaneously, and coordinated closely with each other and with Dave Mack through e-mail and in-person conversations at Shore Leave. There was plenty of cross-pollination of ideas, and ASD was as influenced by us as we were by it.
Yes, ASD was the first of the four "Cleaing Up" books to be published, by one month, but that doesn't mean anything, since it takes many, many months to write and edit a book. The order in which the books were published had more to do with author schedules and convenience than story content (heck, my book was the second one published but is chronologically last -- and ASD is the third of the four in chronological order). For all intents and purposes, the four books were developed and written simultaneously. Except for Full Circle
-- the process of reinventing Voyager
had actually been underway for over a year when Destiny
and ASD came along; Full Circle
got further delayed when it was necessary to incorporate the game-changing events of the trilogy (and Before Dishonor
) into its storyline. So Kirsten was working on hers before any of the rest of us got involved.
Also, I don't see why you'd see the different branches of Trek Lit as something created by a single book. The different series were always separate, telling their own stories, running at their own paces. Destiny
was an exception to that, the first time there was a full crossover of multiple crews (as opposed to a loose crossover where each crew dealt with a separate aspect of a common problem or theme, often at different times). The "Cleaning Up Mack's Mess" books were about getting back to the status quo where the various series ran independently, the way it had been before the trilogy.
So A Singular Destiny
wasn't the lead-in to Full Circle, Losing the Peace
, and Over a Torrent Sea
, except in the irrelevant sense that it happened to be published first out of the four. Rather, FC, LtP, and OaTS were all continuations/resumptions of their pre-existing series (though more a reinvention than a continuation in FC's case), while ASD was more a continuation of the unique, non-series-specific elements of Destiny
(as the title suggests) and laid the foundations for future books involving the Typhon Pact. It wasn't the source that the other three series sprung out of, but a separate track that started something new while the other three series resumed their previous independence.
Although that independence didn't last long, because the sales department's desire for another big, umbrella-titled crossover event meant that several subsequent TNG, DS9, and TTN novels have gotten published without their respective series titles under the Typhon Pact
banner. But that was a later decision and not part of the original plan.