Not sure if I understand how the referred-to press release is "against free speech" by "allowing rich and powerful to silence critics on Facebook". Does it mean if I am rich and powerful I can have arbitrary posts taken down that I don't like?
The mere fact that he's financing a lawsuit against a major customer/partner of Facebook should be enough to have him removed from the Board. He's actively working against the company's interests.
This post is reaching to try and make its point. It is correlation without causation.