In this scenario the artefact in the core folder has been replaced with the upgraded artefact and the customer wants to use this artefact. The customer is currently using the core artefact i.e. no changes have been made to the artefact by the customer. No modifications need to be made to the artefact as the customer will now use the upgraded artefact in the core folder.
An example of this is a change to the DW_ADDRESS_ETL meta data. There has been an upgrade to this ETL to include a new destination field. Since the customer has not modified this ETL before the upgrade and wants to use the upgraded version then the customer can import this upgraded ETL into the ETL tool and use this instead of the pre-upgrade version.