It's not an "official" government page, it's FACEBOOK page used by the state. No ones rights are being violated, the constitution doesn't apply to social media and it's a JOKE lol. Pages I moderate on FB have specific settings to where
specific words cannot be used to prevent spam and unwanted comments, no ones rights are being violated and to be a member specific requirements are must be met.
You are confusing Facebook "groups" vs Facebook "pages". The USSC has ruled that a social media page run by a government agency IS considered to be an "official" government page, and cannot block/censor the public from commenting on it.
"The First Amendment, which protects freedom of speech, generally prohibits government employees from censoring public comments or blocking access to a social media account that offers official communications."