Agreed. The roots still in media may be dead and gone, and the plant is just using the pot as a mount, like any other piece of bark. But what's going on in the pot seems to be irrelevant these days compared to the past. In years past, potted phals never grew new roots (above or below the media) and when they looked stressed, I pull them out of the pots generally to find a pretty traumatized plant.
Now they are never sick. They just keep getting new leaves and roots (granted usually above the media though occasionally I do see new roots heading into the media). So I don't have any reason to take them out of the pots for root inspection or repotting. If they are in clay plots then I worry more about breaking and tearing roots that have attached to the clay pot.