I think that would be nice to have some buildings from last map updates in BeamNG.drive. Like, updated ECUSA buildings, some WCUSA buildings, probably even Italy or updated Utah buildings/structures as well. Most of the maps is still use buildings from old version of ECUSA and World Editor is definitely needs a updated buildings IMO.
If the map uses outdated buildings, it's because those assets were imported from an outdated map. There aren't any assets built into the world aditor afaik (besides maybe textures)