Depends on many factors. Ex. The technical architecture and configuration of the sas enterprise miner environment, how the libraries were defined and how one deletes the project. The documentation explains the following: When you delete a project that you have open in Enterprise Miner, both the SAS metadata entry and the SAS workspace server project files are deleted. When you delete an Enterprise Miner project via the Enterprise Miner View Metadata action, or via the SAS Management Console, only the SAS metadata entry is deleted. In such cases, you will need to manually delete the SAS workspace server project files as well.
It could be more complex if your organisation implements rules because of regulatory and/or data governance requirements.