If “Good Morning America” or “World News” look any different in the coming weeks, it might be because ABC News is employing nearly 400 fewer people. David Westin, president of ABC News, said this was “a difficult time for everybody” involved. Brian Rooney, an ABC reporter in Los Angeles, was let go. Earlier this week, ABC News, a unit of the Walt Disney Company, largely completed one of the most drastic rounds of budget cutbacks at a television news operation in decades, affecting roughly a quarter of the staff. The cutbacks promise to change ABC both on- and off-camera. For...