Actually, the Federation was not utterly trashed. It came extremely close to being so, and there were some key worlds that were indeed put to the torch, but the majority of Federation worlds were actually left untouched. Yes, the entire Federation was shaken by the final Borg assault unlike ever before in its history, no doubt, but it was far from totally decimated.While I don't think the events in Destiny are going to be swept under the rug and forgotten--indeed, I expect the consequences of the final Borg offensive to be remembered forever in Federation society--I actually don't think we'll see the books be quite that bleak and dreary. There probably will be references to reconstruction for quite some time, but I don't believe the books will focus too heavily on that. I think it will be more of a case of it being a new world order in the Quadrant and the Federation will be left behind if it gets too complacent...You may have gotten more than you bargained for.
'Destiny', made the borg kill 64 BILLION people, brought the federation to its knees and left it there (the federation had nothing to do with the events that, in the end, allowed its survival).
Beyond the material devastation, think of the trauma the federation suffered: Pearl Harbour or 9/11 times a thousand.
If future novels in this continuity want to be even remotely plausible, you won't be seeing much TOS-like optimism and thirst for exploration or TNG-like self assuredness in them. What you will see is a strong isolationist movement and major social changes in the federation.
One problem - that wouldn't even be close to realistic.
The book line utterly trashed the federation - materially and spiritually (in its selfconfidence, etc); it it assumes such a traumatic event have no effect on the federation psyche - beyond some memorials and refugee camps - then it's not even trying to be plausible.
New order inside the quadrant - fine. What about inside the federation, who suffered the greatest losses?
The biggest loss the Federation suffered was to Starfleet--forty percent of the fleet was lost during the battle. The biggest obstacle in the post-Borg era is that Starfleet is stretched painfully thin and is no longer able to carry out all of its responsibilities as effectively. The phrase "the only ship in the quadrant" is almost as true today as it was in TOS.
As a result, there are some Federation worlds--especially those farther out on the frontier--that are having it more rough than others because of a lack of starships.
It's sort of become crucial to seek out new allies and members for the Federation...