When old, forgotten pages suddenly resurface, they can confuse your visitors...

https://www.scribd.com/document/1016381165/Why-Do-Old-Content-Problems-Show-Up-at-the-Worst-Possible-Time-205018

When old, forgotten pages suddenly resurface, they can confuse your visitors and hurt your search rankings. This often happens through unintentional site scraping or orphaned archives appearing in search results