Optimize Creative For Each Person is a feature available when Dynamic Creative is on that allows Facebook to make some sophisticated edits.
New Facebook Ads Feature: Dynamic Experiences
There’s a new Facebook ads feature rolling out called Dynamic Experiences, that allows automatic enhancements to text and creative.
Facebook Ads: How to Optimize Text Per Person
Facebook allows you to optimize text per person, moving Primary Text, Headline, and Description when it may lead to better results.