according to CIC and base on the information on the website, any application submitted whether study, visit, work before 31 july will have to undergo biometrics again except if CIC received your application on 31 July and after
you won't have to give finger printing upon landing as you've already given biometrics but upon the expiration of your permit and applying for an extension or for PR.. you are to give biometrics again if you have submitted or process your application before 31 July