Years ago Publisher Record Cards were held for 8 years only. That is what identifies you as a member of a Congregation. Though I never saw it in print, general consensus was if you were "gone" (I don't think the term "faded" was applied yet), then you were considered a "man of the world" if something was reported -- as long as you were not identifying yourself as a JW.
As I understand it today, your final Publisher Record Report is kept indefinitely. I believe the reason for that is -- "just in case" -- just in case they WANT to go after you. Generally speaking, if you have faded for several years, they will "let sleeping dogs lie" if you are not agitating things. KInda the idea of "don't go away mad, just go away". But if you become an agitator ie, shit disturber or persona non grata (ax murderer, etc), they can go pull up that record and formally oust you.