Your CPF savings cannot be provided for in your will because the CPF monies do not form part of your estate, which are everything that you own (assets) and everything that you owe (debts) as well.
What happens if my nominee passes away before me?
Below answer from https://singaporelegaladvice.com/law-articles/guide-cpf-nominations-how-to-make-singapore/
When a nominee predeceases you and no new nomination is made, the CPF monies due to the nominee who had died will be distributed to the rest of the surviving nominees in the same proportion as their specified shares.
If no CPF nomination has been made, or if all your nominees have predeceased you, then your CPF monies will be distributed according to the Intestate Succession Act (or according to the Inheritance Certificate, for Muslims).
Reference: https://www.msf.gov.sg/opg/Pages/The-LPA-The-Lasting-Power-of-Attorney.aspx
A will is a legal document which states your last wishes relating to your assets and loved ones after you pass on.
Generally, a will includes a list of the following:
All your assets and liabilities, such as your debts.
Beneficiaries – who will receive the assets and how much each beneficiary will receive.
Guardians – to care for your children until they turn 21 years old.
Executors – to carry out the instructions of your will.
Reference: https://www.msf.gov.sg/opg/Pages/The-LPA-The-Lasting-Power-of-Attorney.aspx
The LPA is a legal document which allows a person who is at least 21 years of age ('donor'), to voluntarily appoint one or more persons ('donee(s)') to make decisions and act on his/her behalf if he/she loses mental capacity one day. A donee can be appointed to act in the two broad areas of personal welfare and property & affairs matters.