You can either retire a product or replace it with a new product. If you only retire the product, it will remain active in CloudPortal and charge the users based on the usage that accrues in the active subscriptions. If there are any entitlements in any subscribed bundles, they will still remain for the product.
You retire an existing product and replace it with a new product. This replaced product will not be charged from next plan of a channel catalog after it syncs with the reference catalog.