The Ansem Report in question doesn't describe the soul "expiring" but rather says that if the soul leaves the body, the body gives way to death. We don't know what becomes of the soul, whether it "expires" or otherwise, and it's also likely not important, since most cultural ideas pertaining to the soul are attributed to the heart in this universe.
Which, departure of the soul itself was never elaborated upon, but it wouldn't seem like a large leap to assume that it occurs alongside any sort of death-event, not just Keyblade attacks. c.f. Mufasa falling into a Wildebeest stampede (it's fair to assume Disney worlds are canon, right? lol)
That aside, the Sleeping Worlds were in their state because they were first destroyed by Darkness, right? So let us not kick that fact aside and forget it. By this I mean to say, if we ever choose to assume Daybreak Town is asleep, then, unless some exception of the rule is at hand, we must assume it first fell to Darkness.
Which in turn is to say, saying Daybreak Town was "destroyed" is an option, even if its "present" state is in Sleep.