DY: Rav Schachter says otherwise. He says if a couple isn’t Frum and then he becomes a Ba’al T’shuvah and she doesn’t, she doesn’t lose the Kesuba for that. The Kesuba is a contract. One of the implicit terms is that they follow Halachah. If that is not the case in a particular instance, then why does she lose the Kesuba?
Ben: You are trying to use an assumption from the Shulchan Aruch to back-read a Gemara. That doesn’t work. How would the Rambam have read the Gemara?