She made a statement and so did the studio, but no one provides a reason.
I hope her injury hasn't permanently scarred her physically or mentally. I really loved the first season, even if I didn't like some of the choices either she or the director made.
She may not have the ability to wait to resume work and couldn't due anything (or what she wanted) with the current contract restrictions.
I wish her love and the best in her life and career.