Yes, unmannaged switches can be used to pass audio successfully over Dante Networks. PreSonus Technical Support through general investigation has found that most switches under $100 in this variety will have Energy Efficent Ethernet (EEE) available which is found to be unsupported on Audinate's website. In some cases, managed switches will have a toggle to switch EEE off, giving the user control of power and port traffic to guarantee packets. While this may work, it still can be a switch that you would want to test thoroughly in your setup before using it in a professional application.
PreSonus Audio highly suggests always using Managed Switches in networks and removing EEE and enabling QoS (Quality of Service) be in place for guarantee packet transfers. For more information, please see Audinate's Networking FAQ's or proceed to this website for specific values of DSCP for QoS packets in Managed networks.