I think what you're referring to is that the tax is an amalgam of the highest personal federal rate plus the highest rate for the province in which the person is a resident, and at zero in the case of Quebec. That's because Quebec is a non-agreeing province with respect to the personal income tax; they levy their own tax through a separate system.
In July, Quebec announced that it would be implementing the same tax, so generally Quebec will mirror the changes we've done. However, it can't be done directly in federal legislation; Quebec does it itself. What the effective Quebec rate is will depend upon what they have chosen.
Our approach has been to tax it at the highest personal rate for whatever the province is. I presume that Quebec would likely do the same.