When a user is deleted from the Everyone user group in Strategy Developer 9.x and newer under Administration > User Manager as shown below:

the following message appears:

Do you want to delete the user profile folders?

If the profile folders are deleted, the user objects will be deleted as well. If they are kept, Administrators will be able to access them under that user's profile folders.
If the user created any objects in the public folder or the schema folder depending on the privileges, those objects will automatically be transferred under Administrator's ownership.