This is my view on how SINP selection works:
First applicant, they would review your application, check and verify all your documents. If you met all the criteria and documents are complete, then they will give you a nomination, then the nomination number is down to 249. If not they will notify first applicant of any reason being not qualified...Then they will go to the second applicant, assuming nomination still on 250. If the second applicant will qualify then they will send nomination and number goes down to 249. And so on…
Just imagine if applicant no. 400 is qualified and was given nomination, while applicant no. 1 is also qualified but wasn't given nomination just because the quota is reached. Do you think that would be fair? It will be on a first apply, first serve basis….Its base on fairness. Does my view makes sense?
Another point is having a nomination from the province doesn't guarantee you will become an immigrant because your application will go on a meticulous assessment again when you apply to CIC Centralized Intake Office.