Google introduced a new ad tracking technology called Federated Learning of Cohorts, or FLoC, that uses a web browser to anonymously place users into interest or behavioral buckets based on how they browse the web. Google began testing the technology in Google Chrome earlier this month and other privacy browser and search engine developers have all removed it from their software or created tools to block it. WordPress plans to disable the technology using the following four lines of code, which will cause the blogging platform to issue a HTTP request header telling the browser that FLOC should be disabled for the site.
Source: https://www.bleepingcomputer.com/news/security/wordpress-may-automatically-disable-google-floc-on-websites/