It is always a good idea after a divorce to update your will or to change the beneficiary designations on your insurance policies and investment accounts. Prior to the divorce it was likely that your wife was your heir or beneficiary. After your divorce, you may not want your ex to benefit from your death.
Problems arise when someone dies and their pre-divorce will or beneficiary designation has not been changed and their spouse is the beneficiary. .
While a disposition in a will to a former spouse would be revoked by a divorce or an annulment, until recently a divorce did not revoke many other revocable dispositions which are essentially like wills (so-called "testamentary substitutes"), such as lifetime revocable trusts (including Totem Trusts), life insurance policies, or joint tenancies (including joint bank accounts).
. . . a divorce or annulment would revoke any revocable disposition or appointment of property to a former Spouse, including a disposition or appointment by will, by beneficiary designation, or by revocable trust (including a bank account in trust form). It also would revoke any revocable provision conferring a power of appointment on the former spouse and any revocable nomination of the former Spouse to serve in a fiduciary or representative capacity, such as nomination of the former Spouse as a personal representative, executor, trustee, guardian, agent, or attorney-in-fact. Finally, a divorce would sever joint tenancies between former Spouses (including joint bank accounts) and transform them into tenancies in common.
The law is applied so as to treat the surviving former spouse as if she/she predeceased the decedent.
So, how to avoid the application of this law? It is simple. Update your will and beneficiary designations after the divorce is granted. Get your ex-spouse out of your will. If you really want to benefit your former spouse, spell out your desire in your updated will.