I’ll bet it will come down to the contract details and whether she was fired “for cause.”
And whether what she did constituted “cause”. From the transcript, she merely asked a rhetorical question during a discussion. It triggered some nuts, but no sane person would construe it as advocating racism. If her blackface/Halloween costume question (or anything derivative of it) was cited as the reason for dismissal, Kelly can claim discrimination, since NBC has other “stars” who have actually worn blackface without being fired. The timing made it clear that the firing was for the “blackface” question, whatever NBC said or wrote about it, and she can probably compel witnesses to corroborate the fact. Prediction: Kelly gets big $$$.