"Freedom of speech" never implied a right to have a specific third party publish your comments for you. It was always about limiting law and government.
The house rules (they're linked in the comments section) cover conduct, not, by and large, content (some exceptions for homophobic / sexist / racist commentary).
"This comment was removed because the moderators found it broke the house rules."
Though it doesn't specifically talk about censorship, freedom of speech was pretty essential to all of these historical pieces. Ironic.