Urukhai, I would like to make a complaint about your post. 

See, while I'll admit that the scouts aren't exactly trying to be stealthy (Angron followers aren't good at it while in space, fair enough) but you wouldn't have learned the name of their race or where their home system is from them. The Nur'xal are insanely paranoid of xeno technology and thus don't use it or incorporate it into their technology without first ripping it to shreds and studying it for hundreds of years. 

So A) Nur'xal communications don't use mass effect technology. Their tech is made differently and thus its highly likely you wouldn't be able to translate the few signals that might be sent out. 

This leads to B) Nur'xal scouts aren't going to be using the Relays to send information home. They're not going to be sending information period. You don't know who may be watching or listening in after all. If the scouts are going to be talking to anyone, its going to be other scouts over short range.