It is not true at all. If that was the case, it would totally defeat the purpose of Access to Information and Privacy act. I ordered GCMS notes 7 times before I got PPR and the most recent one in October itself. BTW, GCMS are just notes from electronic file. They don't even touch the physical file while retrieving the GCMS(Global Case Management System) notes. I even ordered the physical notes from my file and got them back not even a month ago and I still got PPR.
Long story short, at this moment, we don't know how cic is prioritizing old CEC files and ordering GCMS notes certainly doesn't effect the processing of your file.