Sure. The amendment clarifies that, when investigating complaints, the review agency has access to information that is subject to common law privileges under the law of evidence not otherwise named, such as police informer privilege. The intent was always for the review agency, again, to access this class of information, but making this explicit removes any ambiguity.
Finally, Bill C-58 makes explicit reference to privileges under the law of evidence. This raised the possibility that the absence of such language from Bill C-59 could be interpreted as suggesting a lack of access. This avoids that risk by making the review agency's access clear in legislation.