The com.apple.MobileAsset.OSEligibility
MobileAsset type contains a plist manifest of eligibility rules. Most eligibility rules are used to geoblock system features based on the physical location of the user.
The initial publish date is likely around the same time as the iOS 17.4 beta, for compliance with the European Union Digital Markets Act, however parts of the eligibility system existed as early as iOS 16.2, for compliance with the South Korean Telecommunications Business Act.