FYI
1. https://wiki.openstreetmap.org/wiki/Why_we_won%27t_delete_roads_on_private_property
2. https://wiki.openstreetmap.org/wiki/Why_can%27t_I_delete_this_trail%3F

If the paths are visible on the ground it's best to use some combination of abandoned:highway=path or demolished:highway=path or razed:highway=path or was:highway=path along with access=no (no legal access) after many more years if the area has no traces left then we could delete the ways.