Though it needs considerable fine tuning, I can imagine several circumstances where “rape by fraud” is a legitimate complaint.
1) A man goes to a popular singles bar in hopes of finding a romantic partner with the eventual intent of marriage and children. He sees what he believes to be a woman, and makes polite overtures to “her”, to which she is amenable. So he spends time with her, buys her things of value, over the course of several dates, and eventually they go to a hotel room he has rented, where he discovers that “she” is actually a “he”, after sex acts have happened in a darkened room.
By this ruse, he has been defrauded of his time, effort, money, and possibly his good name and reputation, becoming a butt of jokes, and a subject of scorn. And, with a change in the law, he might also be considered a victim of rape by fraud.
Often when this happens, the man is enraged enough to physically assault the fraud, for which he is arrested. Currently, the fraud is no defense, and his case is treated as if he just spontaneously decided to assault the transvestite.
2) A similar situation, in which a man is hoping to find both a mate and have children with her. But the transvestite has had a sex change, so its genitalia appear to be those of a female, but it cannot bear children.
Likewise, this is a fraud, but only if the sex change does not inform their husband of what they really are. Again, the courts dismiss what might be years of fraud against the husband, and his diminished ability to find a fertile wife. He has, in effect, been raped of his fertility, through deceit.
3) A truly vicious deceit is if one partner goes to lengths to conceal that their family has a severe genetic disorder. One such case was of a woman who, abetted by her family, concealed that all male children born in her family were congenitally blind. This remained a secret until she gave birth to triplet boys, all blind.
To describe this as rape by fraud is actually insufficient, but the injustice it inflicted is palpable.
4) The most common form of rape by fraud is, as you might suspect, stolen valor. For the courts to dismiss this in an offhand manner, as they have in recent years, is just despicable.