You can now define Entra ID guest account sponsors using the Entra ID admin center or PowerShell. A sponsor is an account or group that knows why a guest account exists. During operations like account reviews of the membership of a Microsoft 365 group, sponsors can help group owners decide if guest accounts should continue as members or should be removed. I’m sure others will come up with ideas for using guest account sponsors, but that’s what we have for now.
https://office365itpros.com/2023/08/17/guest-account-sponsors/
