even if that were the case, then:
1. users should have been warned first and given a chance to update their bootloader if needed;
2. the error message displayed should be considerably more verbose than what it was.
This is a multi-billion dollar tech company and one with overwhelming control on the OS market. They pushed SecureBoot hard, I still remember the move to UEFI being an absolute clusterfuck for Linux users.
They need to be held to a higher standard. Unapologetically.