Well I do know for her to sign she demanded the same pay and vacatioin (there was a Forbes article on how her and Nathan made the same) which for ABC was a big, big no. That wasn't the first time ABC has done that either (and is probably why everything happened when it did. She demanded the same pay as her male co-lead which in the end got her booted for a potential season 9). The show runners did it but when Stana signed she said she was happy with the direction they were taking Beckett, I kind of think she knew of the "break up" somewhat. She might not have thought it'd go on for so long or they didn't go past explaining XX and XY and the ending that involved the break up.