As Mr Penguin noted the guide was originally intended for UHD titles and Pioneer disc dumps are not helpful in that regard.
Disc dump files created with certain Pioneer model/firmware combinations can be useful when it comes to AACS 1.0 (1080p) discs. The lack of a comprehensive list of suitable Pioneer drives made it easier to stick with a blanket rule that Pioneer drives should not be used to create disc dumps for submission.
Users do still occasionally submit Pioneer AACS 1.0 disc dumps and they will always be processed when possible even though they are discouraged.