As I understand it, clause 4 essentially provides that services that do not have an impact on the achievement of the Canadian broadcasting policy objectives do not have to be regulated.
Since it is possible that some services that do not have an impact on Canadian broadcasting policy today may have a more significant impact in the future, the act provides the CRTC with sufficient flexibility in this regard. Thus, the CRTC has the regulatory power to determine which services could be subject to regulation, to the extent that the activities of those services have a demonstrable impact on Canadian broadcasting policy objectives.
In short, the process seems complex to me.