I think one goal is to at least get the state from before the earthquake, even if many buildings are expected to be gone (and then you can just tag the building as destroyed:building=). But you can coordinate humanitarian efforts much easier if you have a rough idea how many people may* still be somewhere where there have been dwellings. At least in other areas HOTOSM have been active the map data has been validated on the ground as well, but that may depend on who is working on that particular project.