/u/StatCanada has a YT video on the topic:
See also The Canadian Consumer Price Index Reference Paper:
This Canadian Consumer Price Index (CPI) Reference Paper provides an overview of the Canadian CPI. It is intended for a varied audience, ranging from users interested in general information to those requiring more technical or theoretical details. As such, it explains all the important aspects of the Canadian CPI: uses and interpretations, scope, classifications, sample strategy, price collection, index calculation, quality change, weights, basket updates, reliability and uncertainty, special cases and treatments and history.