Why Beneficiary Designations Override Your Will
thebalance.com
thebalance.com
Those beneficiaries supercede whatever is in your will (if you have one).
Here's a rough summary that is not legal advice:
Pros of using a beneficiary designation: The account contents don't need to go through probate before being distributed. There may be some tax benefits for the recipients.
Cons: Because named beneficiaries are account-specific and retained by the bank (not centrally like a will), it's easy to forget to update them.
Either way, it's worth considering (a) for a given account, am I using a beneficiary designation or a will/probate, and (b) are the beneficiaries current?