Just like the Iowa case, you have an argument. Whether it will win or not depends upon many factors including the jury makeup, the judge, the other evidence involved in the situation, etc... Many of the decisions are case by case in this area of the law.
Dear Husband: If your wife is not an owner of the property and it is not your home or residential property, then there is no problem with the mortgage assuming that there are no other issues with the documents.
If your wife is not an owner but it is your home or residential property then the bank will want your wife to sign a homestead exemption. But again, the mortgage is ok. Just subject to your wife's homestead exemption.
If your wife is an owner of the property and the bank knew this at the time, then they probably have a problem with their mortgage. Nevertheless, the bank can still seek to recover the money on the loan although any mortgage foreclosure actions would be very difficult while a suit on the note would not be.
Hope this helps. This is not legal advice and is not intended to create an attorney-client relationship. The post is only an opinion. You should speak to an attorney for further information. The poster is licensed only in IL. If this post is useful to you, please remember to upvote it.