This isn't such a fancy dancy issue as that. This is about allegations about interference in an election by a foreign power, something which is a crime in the states. How does this possibly relate to that? Because all these guys (including the president) lied about the fact they had met with the Russian ambassador. Flynn wasn't fired because he met with anyone, but because he lied about it - to the public, and to the vice president.
That's the issue: lies, misdirection, and perjury.