There are statistics that they cite. I would imagine that Maître Morgan would have provided much of the same information as you have. He's with the Sookman group at McCarthy's.
But there are statistics provided from another survey. Here's paragraph 180 indicating,
...spam originating from Canada had dropped 37% since CASL came into force. This drop had little impact on businesses. There's also evidence that retail e-commerce sales rose in the year of CASL coming into force. It will continue to do so for the immediate future.
There is some interpretation of the statistics.