Chronology is one projection of this site's notes, not the structure underneath them. The corpus is the artifact of record; pages, feeds, and prompts built from it are derived realizations that should stay regenerable rather than independently maintained.
AI generation creates more disposable realizations, but an artifact becomes derived only when assurance can move from its exact implementation to a durable generation and verification contract.
A model can be replaced only when the application retains authority, canonical state, evidence, verification, and recovery outside the model's control.