If you are looking for World War II service men and women who died in action, their files are "Open" and accessible on the Library and Archives Canada Website. Here is the link to the webpage:
https://www.bac-lac.gc.ca/eng/discover/military-heritage/second-world-war/Pages/introduction.aspx
The webpage states: "There are no access restrictions on the service files for members of the Canadian Armed Forces who died in service between 1939 and 1947, including those killed in action, those who subsequently died of injuries related to service, and those who died as a result of accident or illness while in service."
Those are the only files that are accessible right now. Library and Archives Canada made all of the World War I records available only after the last veteran had passed away.