I didn't realize that the outgoing passenger lists lacked detail as to destination!
The John Coule who enlisted in Amherst was married in 1914 to Louisa James. His parents were given as Thomas and Rose Coule. Father Thomas also signed up for the CEF at Sydney Mines. In 1911 Rose Ann(35) with children John(17), William(13), Frank(6) arrived in Canada destined to join her husband in Sydney Mines.
There are various sailings back and forth to England for Rose Ann. Thomas came back to Canada in 1921 and showed a destination of Farnham Quebec and Rose Ann joined him later. Her brother, William Collins, was their contact in Quebec.
There are border crossings for Frank Coule which showed his father Thomas living in Weston, Ontario (part of Toronto). There is also a 1924 border crossing for John Coule, father Thomas of Weston, Ontario. It showed that John had left in 1922 to be married (yet another marriage for John?)
There is a death for Rose Ann Coule of 6 Cobalt Avenue Weston, Ontario. D. Sept 2, 1927 @ 52. She was still married. Buried Riverside Cemetery Weston. Father William Collins, England and mother not known.
If this is your John's family it might give you a starting point in Ontario. Try contacting the cemetery to see who is buried there. The Toronto library will answer emails and do lookups in their City Directories for names and then there is the paysite Pages of the Past - The Toronto Star which you could search for obituaries, marriages.
Information on deaths, etc are a provincial responsibility in Canada and what is accessible varies from province to province. Ontario deaths are accessible up to 1938.
Debbie