There are plenty of reasons to map roads on private property, and presumably it is visible in satellite imagery, so I don't see that as a compelling argument by itself. If we're not counting oceans, most of what is on a map is private property.
"Not visible from an aerial shot with leaves on" doesn't really mean anything. If the roads aren't buried underground or in a tropical rainforest, they are probably visible to a satellite at the right time or wavelength.