If they can prove misrepresentation, then the PR status was obtained by deliberate fraud. They could revoke based on that. Nothing to do with changing your mind AFTER you become a PR.
As of now, there is no way they can prove misrepresentation unless an applicant tells them otherwise because it is an intention. An applicant may not like the province and move out after a month. Unless the terms of PNP are disclosed on IRCC or PNP website about changing provinces, or residency requirements, there cannot be any legal action taken. Many have mentioned section 3 (a) and (b) can be used but there is no law from any province for the same. If they were taking any action, then the retention rates of Atlantic provinces would not be so low.
