^ Exactly. One of the excuses used was that the Enterprise D sets had to be struck anyway to make way on the soundstage for the ones built for Voyager. But it would have been just as plausible IMO to have kept them in storage and then wheeled them out again (with modifications) every few years, just like they did with the Enterprise E sets.
It wasn't as simple as that though, the sets were largely modified to build Voyager - the corridors, crew quarters, engineering were basically redressed versions of the TNG sets.
Probably just as easy to build a whole new set on different soundstages, purposely built for the scenes in the new film, than to redress the Voyager sets, then put them back again at the end of the summer.