The debate over the limits of acceptable speech on social media is a discussion worth having, but the claim in the article does not match the wording of the policy at hand. The policy states that users will get a strike if they claim that “the vaccines will cause you to be sick, spread the virus, or would be more harmful than getting COVID-19" (emphasis mine).
The vaccine causing the spread of the virus is different than the known fact vaccinated people, infected elsehow, could spread the virus.