This is a very interesting idea. I am not ready to implement this just yet (I would like to think on it), but I think the most optimal path would be to have the filesystem ignore hidden routes and have a hook that determines if a player can access a route, by default true. But then when hidden routes get implemented, this logic gets buffed up so that if it is a hidden route, depending on which, it determines a skillcheck or what ever else.
Issues I can foresee is this taking up memory space and also needing a way to clean it up.
Alternatively, a slot-based system that stores the last X amount of deleted file contents. Issue is this would clash with the image rendering and rendering of other things.
There must be a solution, so more thinking needed.