I believe Ottawa's numbers look correct and jibe with what we've seen over the past year. The latest numbers are including Ottawa's increase of 25K and appear to also include their increase last year due to the CMA area addition. Calgary's numbers are what look funny. They have included the 50K bump from last year, but also another 77K (going from last year's 1,481,000 to saying that we were 1,558,000 last year). We're not sure whether the 77k is an undercount or a boundary change, as the 77K is almost exactly what Foothills MD would be. Ottawa's increase appears to include the boundary addition from last year, but might not be the case either, as last year they were reported as having 1,488,000 and now statscan is saying 1,498,000. That 10K difference and out 77K difference looks be undercounts. Undercounts seems the most plausible explanation as the site does mention they are using 2016 boundaries. Also Edmonton is showing higher than was reported last year, but there has been no boundary change there and won't be for quite some time.
Whatever the case is, it will be the same for all cities, so Calgary will have passed Ottawa regardless, and is back in 4th spot. The true numbers should be somewhere around Calgary at 1,608,000 and Ottawa at 1,560,000 (due to last year's boundary addition)
What's impressive to me, is that sometime in the near future we'll see Foothills added, and it'll be another huge bump. We could see Calgary hit the 2 million mark fairly soon.