The ACA had the following to say in their letter:

The ACA is concerned that Bill C-19 contains provisions that explicitly override existing legislated
information management processes. The current disposition of records in the Firearms Registry is for destruction ten years after last administrative action. Further, Sections 12 and 13 of the Library and Archives of Canada Act (LAC Act) require written permission from the Librarian and Archivist of Canada to destroy records. However, sections 29 (1) (2) and (3) of the Ending the Long-gun Registry Act call for the destruction of records “as soon as possible” and that the LAC Act be ignored.

The ACA urges the government to trust the records management processes already enshrined in current legislation. The Firearms Registry records were scheduled according to business needs and to potential historical value by the creating department and professional archivists at Library and Archives Canada. These processes ensure accountability and transparency with regards to the destruction of government records. Destroying records for political expediency and disregarding the LAC Act sets a very dangerous precedent for future legislation and record keeping practices.

The ACA is an academic & professional association that has taken a stance on this important issue which is exactly in their mandate to do.  Excellent.