Not really. A man who assaults a woman with intent to rape and finds her wearing a chastity belt can still rape her orally. It’s likely he can still penetrate her anally as well since the hole must be big enough to allow for elimination without allowing too much fecal material to accumilate and become unhygienic to the point of causing life threatening infection. If you’ve ever seen one of the “replicas” in a museum, this is readily apparent.

Further, a man “thwarted” by a chastity belt can easily overcome the barrier and further humiliate the woman by raping her through the slit allowing for urination using something other than his penis. Like, a dagger or a sword.

Rape is not and has never been about sex. It is about power through violence and humiliation.

Chastity belts were never about protection or fidelity (Fellatio is still adultery). They were always about control and humiliation (even as a joke).