The key is that it's a very important measure, the capital gains exemption for principal residences. It's something that had strong support. The idea is to make sure it's being used by the people for whom it's intended—that is, Canadian residents living in principal residences. The idea is to be better able to screen out non-residents who, through certain provisions, have been able to claim the principal residence exemption when that was not intended. It's an important part of the tax system, and the idea is to make sure that it continues to work well.
On November 2nd, 2017. See this statement in context.