For Trados Enterprise Customers with Custom Workflow Editor, this should already be possible today. You can create a new human task that you place in the workflow after Copy Source to Target.
This enables you to open the file in the Online Editor and perform actions or Preview the files. With the recently released "multiple outcomes" you can then re-run certain tasks if needed.
This should adress a portion of what has been described here.
The use-case of previewing segmentation is something that is on our backlog for future.