If they return the application (as incomplete) again then you might need to apply for restoration of status (if its within 90 days since it expired).
If its not returned then you will be safe (they normally wont return applications if you have received AOR), you will be considered to have status until the day the decision is made on the OWP application.... you can legally
stay in Canada until a decision is made on your OWP application because you have implied status. And if for whatever reason the OWP is denied, you will be able to apply to extend your visitor status.