This happened deep in the Twilight of Man campaign. I have been fighting as an Uruk of Mordor and have defeated most factions between us and Dol Gundur. The lords of Dol Gundur sieged Woodsmen village, I helped them, we razed it, but the ruins can still be accessed. As a matter of fact, I, as an Uruk, can access it and buy stuff from it and do everything you could do in a settlement. And on top of that, Dol Gundur's generals are stuck trying to siege it over and over. The village can only be accessed when its under "siege" by the lords, but I am able to do jobs for the faction and buy items from them. I also find my own character as an npc lord in that village, and any instance of him mentioning a faction is replaced with Player Faction.

I have not activated cheats and I am not truly sure whenever or not I had an older version save file that got updated, although it might be quite possible.