I believe it's usual for actors on a series which has an iffy chance of renewal to have a certain cutoff date when they're free to look for other work.
Yes, I have to be very selective in sites that I read when I'm really busy and don't always have a chance to see a show on the night it's telecast. It took me three or four days sometimes to catch up with the previous Sunday's Political Animals broadcast.
The season finale threw in quite a twist that caught me completely by surprise.
I'm not getting my hopes up for a second season. Though the ratings did improve a bit by the end, they were not stellar, and the show must cost a pretty penny with this star-laden line-up.