"AnswerBag still has many old membership accounts (mine, for one), which make the membership and site look more active than it really is." I don't know if they kept any of the old posts, as I haven't looked into it that closely.
What are you folks talking about? AB is awfully quiet, but not dead. I mean the site still loads and even has four current posts. (Post # above 3,490,000 is a current post.) That is up from one or two per day since I stopped going there. I stopped because of several ill-mannered jerks fussing at me. They don't go there any more either. And we were almost the only members still active.
But to answer the question, posts are kept in an archive. That's where most of the current activity is coming from. Most of the questions you see are over nine years old.
They may still be around if a spider found them, or if they made an appearance on websites like the Wayback Machine. If not, you are out of luck. Probably.