The hijab is very much a religious symbol. The keffiyeh as well, to a much lesser degree.
To ban one and not the other is a violation of the persons rights. I don't care if it from an employer or not, fair across the board is the only way to play it.
If it were a Private institution, office, business, whatever.... then the employer has the right to set their own rules for wear. SSU is a public University, so that is not in play here.
(as a side note: I am atheist/agnostic, so I don't have a dog in the fight. No bias here at all. No "right wing agenda")