The claim is that Fb is most definitely not a monopoly on access to political speech. People are not stuck in an information vacuum the moment Facebook bans their favorite content. People who want to access Alex Jones can still do so easily.
What Facebook IS a monopoly of is getting your content to go viral. I argue this service is not speech. Which is why I oppose web hosts and cloudflare censoring content, but support social networks banning users. When web hosts do it, users who WANT that content can't get it anymore. When social networks ban people, they merely can't find new eyeballs that never specifically requested that content.