I looked into this a bit more, and it seems Ubuntu is basing off of linux-firmware at kernel.org and not following Debian's use of firmware-misc-nonfree. I'm removing the watch related to firmware-misc-nonfree, but there appears to still be an issue with update-initramfs and the i915 firmware for Kabylake and Broxton systems.
I looked into this a bit more, and it seems Ubuntu is basing off of linux-firmware at kernel.org and not following Debian's use of firmware- misc-nonfree. I'm removing the watch related to firmware- misc-nonfree, but there appears to still be an issue with update-initramfs and the i915 firmware for Kabylake and Broxton systems.