Date of extraction could be added to the Details window for a player though since I dont make stuff just break it I dont have an informed answer to the difficulty of such. I can only say that Dracomet has comments on more than one occassion on how unpleasant our UI is to modify but hey they can only say Hell No if we ask right?
One other problem however is the RP problem for that part of the community that does so. Many Machinists and Merv players RP their character's in such a way to reflect they are no Redpills but exiles or other programs. If no good terminology could be used in the UI I doubt any chance would be implemented because it would need to satisfy most (all is impossible) folks.