The poor will have scavenged the abandoned buildings in built-up areas, yes. Still-occupied buildings and those in smaller towns with no easy access to a scrapyard are more likely to be intact. So it’s more likely to be a case of “these are no longer to code, they are not grandfathered, you have a two-year grace period to switch them out” (staggered geographically or by building classification to avoid a run on plastic pipes) plus “road trip!”

We might also end up mining older dumps for stuff discarded when copper was cheaper.