They are starting to encrypt the ecm and many of the modules that connect to them in the interest of cybersecurity making it nearly impossible to swap around parts. Over the air updates to the ecm can now be performed on the newer vehicles (requiring fewer trips to the dealership in theory) but also opening the possibility of your vehicle being hacked by outsiders. This also makes it much harder to delete or add performance enhancements. https://www.musclecarsandtrucks.com/c8-corvette-gm-evaluating-next-steps-regarding-ecu-encryption/