Nexstar Media Group, the nations’ largest TV affiliate owner, thrust itself into the spotlight last month as Jimmy Kimmel was yanked off of ABC in a controversy that exploded into an extremely public battle over free speech.  Though that September standoff has since been resolved , the episode brought to light the seldom-discussed relationship between affiliates and its pending $6.2 billion merger with rival Tegna , one that would give it unprecedented reach in the U.S. Critics say the merger