Speccy, or any software, wouldn't be able to interrogate what ports are available on a monitor.
Based on the monitor and graphics card models that is finds, I guess it could do a lookup on the manufactures web site for specifics or keep its own database but that would be of an order of magnitude above and beyond what I would deem justified for such a small, simple tool.
For the scenario you describe, I would feel safer knowing I did that research myself, looking at the graphics card and monitor specs than relying on Speccy to guess the answer for me.