Not true.
While Immigration is a federal subject, on which the federal government has complete control, the federal government has given certain privileges to Provinces to attract prospective immigrants to those provinces. PNP, is a part of that deal. However, even when a province nominates a prospective immigrant, it is the federal government through IRCC, which will make a final decision in whether to approve it or not. IRCC is free to seek additional information, verification documents from Provinces and the verification is not like that for IELTS or WES ECA. It is more deeper, where the IRCC will explore whether the Province has picked up someone who has a genuine interest in moving to the province and will establish themselves there.
There has been a case where a province nominated an applicant, but the IRCC refused his application citing concerns on his intent to settle in that province. The court held that it was the sole prerogative of the IRCC to make a decision and the Province can only nominate, but not have a final say on whom to admit and whom not to. This is why IRCC will ask for settlement plans from some PNP applicants to ensure that they are not using PNP as a means to seek in. (See
Deol v. Canada (Minister of Citizenship and Immigration), 2013 FC 1147; and Noreen v. Canada (Minister of Citizenship and Immigration), 2013 FC 1169).
Read my post to understand how the immigration with the PNP and the federal system works:
http://www.canadavisa.com/canada-immigration-discussion-board/threads/understanding-pnp-its-obligation-to-live-in-province-and-pr-status.502209/