It's very interesting that you highlight the access to one's own information, which is likely the way the Privacy Act is used most often. It most immediately has an impact on the lives of individuals who are employees of the government, but also individuals who want to know the basis for decisions that are made about them.
A central maxim of privacy legislation is access to one's own information. It's interesting that these recommendations don't suggest a significant overhaul of the access to one's own information. They relate to the collection, use, and disclosure of personal information by government institutions and by public bodies.
To ultimately answer your question, I hope, I don't think the changes we have suggested are going to dramatically change that and either lead to a stampede of individuals asking for their own information or somehow restrict or hamper supervisors in that particular capacity.
The one that comes to mind, which would most particularly have impact on that, would be the requirement that one collect only information that's reasonably necessary. I could see it happening, for example, in the hypothetical situation you put forward of somebody doing an evaluation of potential candidates for employment or promotion. If the supervisor has used information that really isn't necessary or relevant to that decision, they would have crossed the boundary within the privacy legislation. They would have gone too far in collecting information that likely would be irrelevant, or too intimate, or what have you.