HDMI-CEC connections have a logical address assigned depending on their functionality as defined by CEC specifications. This allows a HDMI-CEC to fulfil a number of functions through a single device (e.g. switching all connected devices to standby, use of the menu of another device etc.).
Similarly, Thunderbolt interfaces support wake on LAN and as such can be remotely enabled from a sleep state. Furthermore, they can be used to tunnel display as well as data (USB/PCIe) from a host/endpoint to a host/endpoint/display. Each Thunderbolt device is assigned a topology ID (address) to enable the mapping and directing of the different data types to the proper destination, IDs being relative to the root (host) and assigned by the connection manager based on the position of the device.
In conclusion, both HDMI-CEC and Thunderbolt connections, as associated to a network address and being able to transfer network information/commands, are considered network interfaces or network ports, and they should be treated as such.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.