Jinoh Kang (@iamahuman) commented about dlls/ntdll/unix/system.c:
system_args.version = system_version; system_args.serial_len = get_smbios_string("/sys/class/dmi/id/product_serial", S(system_serial)); system_args.serial = system_serial;
get_system_uuid(&system_args.uuid);
derive_machineid_to_uuid(&system_args.uuid);
This changes the system GUID. Some DRMs and copy protections like to assume that things like System UUIDs are permanent and never change. Changing this will break such apps and the user might have to reinstall/re-purchase them again.