The desired behavior you described can be achieved using the Feed To Post import method, using the [#item_url] tag. During the import process, navigate to the Map Content section, specifically within Post Content. In addition to adding [#item_content], you can include the specific phrase you mentioned: “Hey, this article was first published on [#item_url]”. Check this case for reference.
For more details on using Feed To Post and magic tags, please refer to the documentation here.
If you have any further questions or need assistance, feel free to ask!