You can check the connector status of the GPU using ADL. This will give you information if a display is connected and how it is connected, e.g.. if DP, DVI, VGA etc.
Please check the function ADL2_Adapter_ConnectionState_Get. The ADL SKD includes a sample called EDIDSampleTool. The code shows how to get the connection state of all connectors. Please check EDID.c function getEmulationStatus.
Chris