Going through a divorce comes with a lot of decision making, especially if there is a lot of property hanging in the balance. As you and your ex make decisions about what will happen, you have to think about everything that might happen.
One unfortunate thing that might happen is if your ex passes away during the divorce process. This development throws a huge wrench in the process. It is especially troublesome if you and your ex have already come up with the property division settlement and haven't yet gotten the divorce finalized.
Here is where the issue comes in. There is a good chance that your ex's heirs would benefit from the terms of the divorce settlement based on the fact that you already signed the settlement. Even though it hasn't yet been finalized, the heirs might still be able to stake claim to the assets that your ex was going to get.
You and your ex can add clauses in the settlement agreement that would prevent the contract from being legally enforceable if one party dies before the divorce is finalized. This could help to ensure that you would get the assets in question instead of them going to your ex's heirs.
As is the case with everything related to divorce, you should take proactive steps to ensure that your interests are protected. You should think about what might happen and try to plan accordingly. Asking questions about certain aspects of the divorce that are concerning to you can help you to gain an understanding that you can use to make informed choices.
Source: California Lawyer, "Death During Dissolution," G. Randy Kasten, May 01, 2017