This article explains how to use PowerShell to remove licenses from disabled accounts, including some caveats such as not removing Exchange Online licenses. Organizations might want to do this to save money on Microsoft 365 license fees while an account is temporarily unused. Removal of Exchange Online licenses can result in the loss of a mailbox, and you don’t want that to happen if you’re disabling accounts just because someone is on a long-term sabbatical or other leave of absence.
https://office365itpros.com/2023/10/11/disabled-accounts-licenses/
