Honestly, it sounds to me like FOX didn't want her back.
Actors usually get a significant pay raise for re-upping their contract for another season of a long-running hit show. Instead, they offered her a 40%+ pay cut. Yeah, I think they wanted her gone.
from what I understand everyone shy of Hugh Laurie and Olivia Wilde, who were both previously contracted for an 8th year and thus no negotiations were needed, have taken a pay cut. Robert Sean Leonard (Wilson) is getting his in the form of a reduced number of appearances... by some reports he might only be in as few as 6 episodes next season. Peter Jacobsen (Taub) and Omar Epps (Foreman) accepted the smaller salary outright, and as of today Jesse Spencer (Chase) is not signed at all.