I don't believe any of those articles. If you want, you can't post the mechanism. I see no viable straight forward path to O-isopropyl methylphosphonofluoridate using NaCN at all.
You appear to be correct. I looked at the molecular structure of sarin and I can't see how sodium cyanide NaCN would come into play. The articles were written by journalists and not chemists so all chemical agents are probably the same thing to them.
I did see that sodium cyanide is used to make the nerve agent called 'tabun' and that Iraq had produced tabun before.