I work as a repair tech for Batteries Plus, on the X and above what usually happens is a notification in the settings app about being unable to verify whatever part is an OEM part and that the service log for the device has been updated. If it’s the battery that is being changed and it’s not paired, it will lock you out of viewing Battery Health information, and if the repair shop doesn’t copy over some data from the original screen then the replacement screen can cause the loss of True Tone. Haven’t experienced a phone completely brick itself because of third party repairs but Apple certainly forces a loss of functionality simply because they want all repairs funneled through them.