Stale content resurfacing from old archives can confuse users and hurt your SEO...
https://stateofseo.com/should-i-301-redirect-old-urls-or-leave-a-404-the-reality-of-content-decay/
Stale content resurfacing from old archives can confuse users and hurt your SEO rankings. Instead of letting forgotten pages clutter your site, start with a thorough content audit to identify what’s still active