And while I appreciate good updated content, I still insist that the _publish_ date should not change. In your case, the publish date ought to be many years ago

And while I appreciate good updated content, I still insist that the _publish_ date should not change. In your case, the publish date ought to be many years ago. The _updated_ date, however, may be re-written with those refreshes. Content should include both (when applicable) and indexes should reflect this.