Thus, the Activation Lock feature that was heretofore valid only for stolen iPhones, is now active for their components as well, ostensibly to prevent disassembling stolen iPhones and selling them for parts.
“Requested by customers and law enforcement officials, the feature was designed to limit iPhone theft by blocking a lost or stolen iPhone from being reactivated,” says Apple, and adds that “if a device under repair detects that a supported part was obtained from another device with Activation Lock or Lost Mode enabled, calibration capabilities for that part will be restricted.”
Those who tested the Activation Lock expansion were indeed asked for the Apple Account password from the device the part was taken to unlock and verify the used component.