Your estate plan should accomplish various goals. Firstly, it should set out options in the event you fall into serious ill health and cannot speak for yourself. Secondly, upon your death, it should facilitate the transfer of your assets to those you choose.
It can only achieve this if it is up to date and reflects your current situation. If you have just gotten divorced, you need to revise your estate plan, as your situation will be considerably different from a few weeks ago.
You probably do not want your ex acting on your behalf
Assigning legal and health care powers of attorney is one task an estate plan should cover. Many people choose their spouse for both of these roles. They can sign papers and pay bills in your name if you cannot due to severe illness. They can also speak to doctors to inform them of your wishes regarding any treatment you might need.
If you still get on well enough that your ex is happy to continue in these roles and trust them to always act in your best interests, then great. But most people will want to choose someone else.
You probably do not want your ex receiving any of your estate when you die
Once again, if you still wish to leave things to your ex when you die, that is fine. But, most people prefer to allocate their assets to someone else. Updating your will alone might not be enough. If you have your ex as a designated beneficiary anywhere, you should go to that asset and name a new beneficiary.
There is a lot to deal with when you divorce. Getting help to learn more about your estate planning options is wise.