No, I'm not talking about the blue wall of silence. I've worked in provincial, federal, and municipal government, and there are in my experience employees who are not going to be persuaded that coming forward with allegations is a good thing to do—a small percentage.
There is another percentage of employees who are not going to go to an external framework. In my role I've experienced employees who, when you raise OPSIC with them, don't want to hear about it; they don't want to deal with it. They actually have confidence in the organization to deal with it.
But to get directly to your question, they might not trigger the PSDPA as a way of dealing with their concerns. I don't think you should read the numbers of PSDPA disclosures in isolation from other things that an agency may be doing by way of reports that come forward of things that are broadly understood as wrongdoing, but that are managed through other processes or for which there are disagreements about how things are approached.