Read the Article in the link. After June 11 2015 they will keep sending back the entire uncomplete application until it has all the supporting documents. Your application is Considered "Locked In" for that date and you still qualify for that date for filing. But you have to use the same application.
Quote From CIC:
For applications received at the CPC-S on or after June 11, 2015
An application must be complete to be accepted for processing and is considered complete only if all of the following conditions are satisfied:
•the application is made in the form and manner and at the place required;
•it includes the required information;
•it is accompanied by any supporting evidence and fees.
The date a person signs the application form is the date of filing. It is important to note that this is not the date on which the application is determined to be complete and accepted for processing. Where the date on an application is more than three months old (90 calendar days) when received (staledated), or where the date is a date in the future (postdated), the application will be treated as if it is unsigned. An unsigned application is not a duly completed application and will be returned to the applicant. See also the transitional provisions.
► Additional background information
Guidelines
▼ Using the same application
It is not necessary for the applicant to submit a new application kit or to re-sign and redate an application every time an application is returned for incompleteness. If an application is signed and dated, not postdated or staledated, it is considered “locked-in” on the date that it is originally signed and dated. The filing date is used to maintain, for example, the original residence calculation. Therefore, the applicant(s) must provide the missing information and/or documentation and resubmit the same application.