I’m slightly late to the party but this is an incredibly useful feature in MacOS 26 ... Apple has enabled the ability to remotely enter the FileVault unlock password via SSH when a headless Mac with FileVault turned on is rebooted.
No more “whoops the Mac got rebooted where's the crash cart" or “how do I access the KVM again” issues!
Open a terminal and type "man apple_ssh_and_filevault" for details, or see the note near the bottom of this page https://support.apple.com/en-us/124963