I hope I have fully understood your question.
We have put in a recommendation with respect to safeguarding personal information. An important aspect of safeguarding information is to make sure that it's safely and appropriately destroyed when it's no longer needed. That also goes hand in hand with the necessity requirement, that information should really only be collected and used if it's necessary. If it's no longer necessary, it should no longer be kept. At the end of that, principles of safeguarding would require that information to be destroyed.
PIPEDA also permits that information to be made anonymous, to have all the identifiers taken out. Statistical information can be very useful at the end of the day, so you're not throwing out all the value of the information, you're just removing the personal identifiers, which is analogous to its destruction. But destruction is an important part.