I like this novel, but i was talking more about the changes of the Borg from a techcollecting real collective to an assimilation driven, queengoverned Hivemind than the technological changes and the natural born Borg the TNG Crew met.
That's a change in the way the writers approached the concept, but that doesn't mean it's a change in-universe. When two stories offer conflicting ideas like that, it's often necessary to reconcile them in-story, to present a way that they can both be true at the same time. This is what I did in GTTS. I explained that the shift of the Delta Quadrant Borg toward assimilation over incubation was a response to the war with Species 8472 depleting their numbers, requiring them to "recruit" more aggressively to rebuild their drone population. The reason the TNG Borg were different is because we were seeing a different subset of the overall Collective, adapted to different needs and circumstances. Incubated drones were preferred on cubes operating that far from Borg space, because they had no prior identities of their own and would be less prone to revolt if they were cut off from the Collective somehow.
After all, the Borg are supposedly great adapters, so it's only logical that Borg in different parts of the galaxy, in different circumstances, would adapt differently. If they were all completely uniform everywhere in the galaxy, that wouldn't be adaptive at all.
