Not necessarily. They might die of other causes first.
There are several things in this discussion that make not much sense to me (a non-Norwegian):
* How would a divorce court refer to a (confidential) medical diagnosis? In some countries, at least, even a criminal court cannot easily access such things.
* Why would the law refer to a diagnosis of a particular disease (when the patient might still be healthy) rather than refer to actual cognitive impairment?
* What's the hurry? Can't you get a divorce fairly quickly just by moving out and filling in some forms?
* One of the major legal implications of divorce is that you don't automatically inherit or get insurance pay-outs. Not the most obvious thing to want when your spouse has a terminal illness, though in some cases you know there's no money involved. Even if you're named in the will there may be bad tax implications if you're not married to the person you're inheriting from.
* Someone mentioned children, but divorce doesn't have to relate directly to children: courts have to deal with the children of unmarried couples, and they have to deal with the children of couples that are separated but still married, so I'd expect a court to worry about the relationships and the welfare of the children and not to care very much whether the parents/guardians are officially married or not.
I would guess that these are all areas of law in which there are a lot of differences between jurisdictions.
