Event details
Microsoft Secureboot FAQs mention that secureboot devices that do not get updated, should continue to start and run normally after June 25th, 2026, but do you guys have any ideas if the UEFI in some servers will start prompting for certificate expiration, etc. after reboots? I am not sure if that UEFI behavior is known, but it would cause us issues.
There is no such thing to be expected. Some vendor software running within Windows may of course warn about it (like they do for not applied cumulative updates), but the UEFI itself is not expected to alter the boot process in any way (this includes requiring more or fewer F1 keystrokes) after the certificates expired.
But as said in the AMA, if you have any fears, test it. Take a test machine that you can reboot and mess with, adjust the hardware clock, and see whether it still boots as before. I would bet it does.