Once a Will is probated it too becomes public knowledge. As said posting info makes creditors and interested parties aware that an estate is now in probate. They can then file so they get payment or contest the Will.
I know a family that a brother, who was executor refused to give certain beneficiaries their share. By making the Will public, they can see that they are beneficiaries and sue for their share.
Creditors can make a claim on estate. It’s part of courthouse public records. If someone thinks they are an heir they can turn their name or if someone objects to the person named executor they can say why they don’t think the person should be executor. As Pam Z wrote, they are also published in the newspaper.
https://ez-probate.com/learn/blog/are-probate-records-public/
I know a family that a brother, who was executor refused to give certain beneficiaries their share. By making the Will public, they can see that they are beneficiaries and sue for their share.
Just in case dark matter wondered. Once something hits the courts, it is public, excluding only cases regarding minors is redacted.