Personally I would not dare to remove a highway=footway under dense tree cover just because I cannot see it on aerial imagery (https://www.openstreetmap.org/way/20497218). Also, in their missives to DWG/OSMF the land owner has not claimed that these paths do not exist - just that they were on private property. But if you have used the same reasoning here as in other parts of Virgina and it has worked well then I'll trust your judgement.