I can't really tell, I had 4 symptoms of past problems suddenly escalating on day 6 last time I took the fast, and since then I never experienced them again (so far), so there might be something interesting going on. It's possible autophagy and fat burning might remove some "memory" but I have no scientific explanation for it. My theory is that as body doesn't have to fight all kinds of pathogens coming in from food, it can start correcting internal problems/mistakes instead with the same processes it normally uses to fight external threats.
Many people report feeling older injuries/illnesses during prolonged fasting. It's not clear what is the nature of that, if it's just psychosomatic and some neural pathway is correcting/readjusting/"backpropagating" itself (think phantom pain) or if the original repair was "temporary" and body does a proper rebuild there, or something completely different is going on. Try 1 week then tell us if you felt something similar, I did.
EDIT: This Reddit thread has interesting comments, elevated HGH might be the culprit: