There may be a draw back to having one set of criminal laws for an entire country. The federal government has to depend on enforcement by local LE. This can lead to uneven enforce. Places like Toronto or Montreal ted to leave illegal incall alone as long as no problems exist. Whereas small rural towns are not as likely to let incall operate.
In the US laws pertaining to the sex industry are local laws and thus more evenly enforced. The only federal law is the prohibition against relations with an underage SP in a foreign country. Otherwise, the US federal government isn't concerned with what you do in foreign country or the state of Nevada where prostitution is legal in some counties.
It would seem that whatever the Canadian national government does pertaining to the sex industry, you may see some areas with very lax enforce and other areas being quite tough.