Hope they figured it out since this post is over a year old.If you have deferred your program or you want to defer your program while your study permit application is in progress or submitted... You first need to go to the official website to read these simple rules from IRCC
Click on the link below:
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/service-delivery/coronavirus/temporary-residence/study-permit/eligibility.html