No Way Would McAdams Character...SPOILER
...turn down a job at Today.
But it is an unrealistic movie. So the character is unrealistic too.
We are set up at the beginning, she is career-driven, workaholic, will do absolutely anything for a job and a show.
Then she has a chance for the ultimate career move, and she abandons it for the job where she... well you know.
If the movie even wanted to be true to a character, they just didn't. I know, it isn't Schindler's List.