For sure your security has started, otherwise, CBSA wouldn't have any record on you to release. It seems you are under SS, but to make sure you have to look at the info in the CD (if they haven't redacted the info)
The letter that you see is just explaining the sections of the law that allows them to redact the notes. For CIC GCMS notes, they also send these info and links in the email.
In the past, CBSA didn't redact any info, but as we could tell they will start to redact one day. And it seem that the day has arrived. In the last couple of weeks, I saw a lot of people saying their CBSA notes is also redacted. The same thing happened to me. They just sent me a letter with these sections saying they need more time to decide which info they can release. I think they are still new to this system and don't know which info to redact or not. Hope they haven't redacted that much for you.