Freedom of speech is only an issue as against a government, which in a free society must always be prevented from using its monopoly on initiating lawful violence to suppress dissent. Facebook is a private company and has as much right to censor its content as I have to censor the comments here. Not that I do, unless it's spam or might expose me to legal liability, but I could. My gaff my rules. Mr Zuckerberg's gaff, his rules.
It does seem quite extraordinary however that the conference agenda and papers for a conference on "Men's issues" should be closed down for breach of "community standards" while celebrations of, or even incitement to, the killing of police officers are apparently fine.
Just to be clear, I am fine with both kinds of content. As I have written here before, I think incitement is a misguided concept that undermines personal responsibility. If you want to tell me in the comments that you are happy for people to kill white US police officers I will find that useful data about you and will not call the police. In general I want to know if people have vicious opinions; the better to counter or at least avoid them. I have been assaulted by a drunken gentleman calling me "an English bastard" and found only the assault troublesome. The insult was actually useful as it gave warning of the imminent violence and permitted evasive action. I have been called "a son of a bitch" in a professional context when I was a transaction lawyer and – detecting no physical threat – smiled, remarking "I am obviously doing my job".
So I am grateful to Facebook for making it so obvious that it is systematically biased to the Left and its zoo of protected identity groups in their ideological cages. It's useful data. I enjoy using Mr Zuckerberg's platform for social purposes and don't much care what passes for ideology in his mind. Just as I do when watching the BBC, I shall now apply a credibility discount of about 85% to everything I encounter there that is not actually originated by a trusted "friend". Given that Mr Zuckerberg's business model depends on his "customers" trusting him (unlike the BBC which extorts its licence fee by state violence) that's probably more of a problem for him than it is for Auntie.