In Arch Linux
mkinitcpio -p linux
shows
Possibly missing firmware for module: aic94xx
Possibly missing firmware for module: wd719x
git clone https://aur.archlinux.org/aic94xx-firmware.git
cd aic94xx-firmware
makepkg -sri
git clone https://aur.archlinux.org/wd719x-firmware.git
cd wd719x-firmware
makepkg -sri
and then mkinitcpio -p linux
again.
So to my understanding, warnings are that- just warnings. Okey got it. And if we don't like it, take it to the kernel developers (or at least do some research because github isn't the best forum to complain or give suggestions, and to not waste anyone's busy time).