A lesson that a rule or a control has since absorbed can be retired where it lives. Distillation now carries the lifecycle and the retirement record, so a topic settles as canonicalized, enforced, obsolete, merged, or invalidated, naming the successor that took the lesson over. A retired topic stays in place for history and stops being offered as current guidance.
A topic keeps every occurrence that produced it. Reconciling a second observation into an existing topic appends to its provenance instead of replacing it, so the record of what was seen, and when, survives revision.