From that link: “The CBSA has placed a moratorium on applications for participation in the Courier Low Value Shipment Program effective June 3, 2019, until further notice. For additional information regarding the moratorium please refer to Customs Notice 19-12.”

That only applies to couriers who want to participate in the program, not consumers who want to self-clear their imported shipments. A person doesn't need to register, they can just take the appropriate forms to a CBSA office and pay any taxes/duties themselves. Kind of a confusing thing to have posted at the top of a page that seems more applicable to consumers than commercial importers.