macOSDeploymentTarget & osxCompatibility in *.jucer file

My check script detected the new property "macOSDeploymentTarget"in the jucer-file, it seems as a replacement for “osxCompatibility” , but trying deciphering the jucer-code: the old osxCompatibility-ID seems also still to be updated? (updateOldSDKSetting?, for backward-compatibility?, in the Xcode Project Exporter?) What is the difference between the two? Can I rely on macOSDeploymentTarget as the only truth?