As you know by now I don't watch Grey's Anatomy. It isn't that I don't like much of the cast, because I do. For some reason I just never started and I hate coming into a show several seasons late. You just never get into that rhythm or fully involve yourself with the characters. Anyway, I don't need to know anything about the show to tell you they are getting screwed over by Katherine Heigl and don't really care.
Katherine Heigl bad mouthed everyone on that show just like she bad mouths everyone with whom she has ever worked. Katherine was ready and did throw Grey's under the bus until she realized that maybe her movie career wasn't going to be as good as she thought. That maybe getting kicked off a movie might be a sign of things to come and no paychecks to bring home.
So, instead of trying to talk her way out of the last year of her contract, now Katherine is all smiles and hugs and how she loves Grey's Anatomy and she never wanted to leave. She was just tired and cranky and hopes everyone will forgive her and please, keep paying her until she can make it big as a movie star and throw you all under the bus again.
I'm wondering also if she told TR Knight she was going to stay on the show. Maybe she thought, "hmmm, he can go and I can stay and be the biggest star on the show." More like the biggest diva, but whatever works. So, I guess she survives her tumor or cancer or whatever for now.