Ottawa's didn't make sense, even adding Gatineau with it, it wasn't much higher than today's CMA numbers. I don't believe the maps are apples to apples, as the Ottawa map might not have been the updated Ottawa CMA. I didn't take the time to go through and figure it out, but a quick look showed the maps to be similar, but not exactly the same.
That said, there are some things to consider for sure. One is that Ottawa has a much older population than Calgary. The other is that the high tech industry there has been stagnant. Government jobs while increasing nationally haven't been increasing at the same rate in Ottawa. If Edmonton will be 600,000 to 800,000 behind Calgary, It wouldn't surprise me to see Ottawa around 300,000 to 400,000 behind Edmonton by 2049.