I submitted the issue to Mendix and received a response back. Currently there is no way for published services to be deleted from DataHub once they’re in place, but it is a feature they are looking to implement in a future release. So, be very careful about what you publish because currently it is a permanent fixture.
I believe you have been in contact with our product team regarding this issue since posting on the forum.
For those that also might have the same question – there is good news! The removal / archive functionality within Data Hub Catalog is currently in progress. This is likely to be released in the current quarter.
The datahub data sources are added the moment you publish an application on, for example, sandbox. This only happens if an Odata Service is implemented on that application. I would expect that service to be removed from DataHub if you remove this functionality from the application and then republish it. Have you tried this yet?