This doesn't even make sense. If a corporation is a person, then 1A Freedom of Speech means that the government cannot restrict the corporations political speech.
The corporation is absolutely allowed to restrict their users free speech, including political speech, because A) the bill of rights only binds the government, not corporations and B) it would actually be against free speech to compell a private corporation to engage in speech it does not agree with.
Should you be forced to post political or sexual content that you disagree with on your accounts or on a wall at your house? Of course not. Similarly, if you start a business, you cannot be forced to post political or sexual content you disagree with. Your freedom of speech as a business is what matters here.
The idea that we have "speech anarchy" where all people can say anything they want and punish anyone who doesn't reproduce their speech is insanity.