There will hopefully be a clause in the new law whereas clients would only be prosecuted if it was proven that the girl was being exploited or the girl was vulnerable and being forced to work against her will, that's why I like the systems used in Edmonton and Toronto where the girls in massage parlours are licensed, that way the police know who's working where and everything, at least in massage parlours, is under control, for the most part, at least with the inside girls being licensed there's some level of regulation.
Also keep in mind that the administration of federal laws is left to the individual provinces which in turn influence the workings of the police departments within their province, so how any new Nordic law would be enforced by any city police force could vary across Canada from city to city.
For example in Vancouver the police have a hands off approach to this matter and will only clamp down when there is evidence a girl is being exploited or is in danger, why would anyone have a problem with that approach?
And in Edmonton the police there are already employing a Nordic type of enforcement, even before any new federal law has been passed, going after guys who exploit girls, and last I checked all the massage parlours in Edmonton are still open for business.