The Quebec bar will not be expressing an opinion on the minimum age. We are assuming that it will be 18. However, if that age goes up or down, there is the risk, as you say, that someone will challenge it on the basis of age discrimination.
The federal government and the provinces each have jurisdiction in determining a minimum age. So some kind of collaboration is necessary, if it is possible.
I know that some data suggests that we must be careful about age, but that does not automatically mean that the data absolutely proves a specific minimum age. The further we depart from the minimum age of 18, the more we increase—