Does that actually mean anything? Didn't 95% of the company sign that letter, and soon afterwards many employees stated that they felt pressured by a vocal minority of peers and supervisors to sign the letter? E.g. if most executives on her level already signed the letter, it would have been political suicide not to sign it

She was second-in-command of the company. Who else is there on her level to pressure her to sign such a thing, besides Sam himself?

Isn’t that even worse? You write to the board, they take action on your complaints, and then you change your mind?

It means when she was opting for the reinstating of Altman, she didn't have all the information needed to make a decsion

Now that she's seen exactly what prompted the previous board to fire Altman, she fires herself because she understands their decision now.