Actually, I can replicate :-)
I've just recreated the test case noted in my comment above in a VMware virtual machine with the same results. It appears the debconf DB is correct the change doesn't make it through to the initramfs although it does get rebuilt:
root@pristine804:/home/pre500# debconf-show mdadm * mdadm/boot_degraded: false <snip>
Actually, I can replicate :-)
I've just recreated the test case noted in my comment above in a VMware virtual machine with the same results. It appears the debconf DB is correct the change doesn't make it through to the initramfs although it does get rebuilt:
root@pristine80 4:/home/ pre500# debconf-show mdadm degraded: false
* mdadm/boot_
<snip>