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.
No worries, I'm not aggressive, just in point.
These specific warnings are well known, and documented a lot in various places.
Of course, if you get a new warning, you should ask/discuss about it.
The reason -as mentioned above in the comments- is some servers need such SCSI firmwares to operate, while most of us don't use such SCSI hardware.
See this comment:
https://gist.github.com/imrvelj/c65cd5ca7f5505a65e59204f5a3f7a6d#gistcomment-2801492