That is correct. Once you get PR, you will have every right to move as per the Law, people say.Provincial nomination doesn't mean u have to stay in that province for ever is what I heard.
But, the whole purpose of provincial nomination is to invite people to live and work in that province for its growth. And if a candidate is will fully accepting such an invitation has an ethical obligation to live and work there unless it becomes very difficult to do so.
There is no barrier and there is no time limit, it is all about the person.
Its like a rich man taking away a food token from a cup with limited number of such tokens in it allocated for poor people.