My understanding is that the 15-year time frame was negotiated with the Privacy Commissioner of Canada in one of the earlier phases of this. From our perspective, the shortest reasonable time to keep information is always the best. If the 15-year time frame is what has been agreed upon with the Privacy Commissioner, then I think that's fine. We would hate to see it go any longer than that, and we would really like to see the retention periods rationalized between the two countries, because the difference between 15 and 75 years is a lot.
On October 5th, 2017. See this statement in context.