This isn't good / completely accurate information. If you have the PPC, you should send it, but wait until you receive your AOR so they can locate your file.
If you refer to the CEC checklist, it states that while you don't need to send the PCC immediately, it can result in a delay to your application. So basically, as soon as you receive AOR, submit the PCC.
Some countries will not issue a PCC without a written request from CIC, but that is a different situation.