Answer
No — documents attached through Document Object Connections can only be printed via the Aurena Agent, and a workflow has no way to invoke the Aurena Agent (which requires an interactive client session), so a workflow genuinely can't drive this kind of automatic printing on its own. The practical workaround is to have the workflow notify a user with a User Task instead, telling them a specific attachment needs to be printed, and let a person complete the actual print step manually through the Aurena Agent.