It isn't classed as advertising, it's a promo. Promos do not go towards advertising minutes. There are/were slight deviations with regards to how many American themed promos that can/could be run. Log-wise, there is a different class for both. If stations could, they would run one or two 30 second promos an hour and fill the rest with paid for commercial content.
However, and I wish to be clear on this, stations promoting their own programming is not commercial content. Not even a smidgen. There are ways around commercial content rules that have been bent with Closed Captioning Billboards and the weather bugs some stations run. There was a grey area and it was exploited. Promos? Nope.
American stations do this as well, so it isn't some coy plan by the Canadian networks to somehow get more money by circumventing outmoded revenue models.