But aren't they applying to be a student in the US? Who is US to decide if a non-citizen can or cannot have freedom of speech? What a tone deaf comment was that!
Many of the rights US residents have don't apply to visa applicants.
In any case, there are plenty of examples in the past where the US denied people entry based on stuff they've publicly said/written. What's different here is requiring you to disclose all your handles and make them public.