Closing this as NOTABUG: After discussions with the author of sg3_utils, it has come to light that most ATAPI devices generally do not claim compliance with this specification and it is not expected that these devices will adhere to the current version of the specification.
As such, do not use sg3_utils with the --id flag or --page=0x83 to try to get the WWN of an ATAPI device. Use --ata instead.