>This is due to one important caveat: to ensure reproducibility, the pacman keys have to be stripped from the image, meaning that pacman is not usable out of the box in this image.

>Users will need to (re)generate the pacman keyring (by running `pacman-key --init && pacman-key --populate archlinux`) before being able to update the system and install packages via pacman.

Interestingly, this approach is how archlinuxarm has been distributed all along. https://archlinuxarm.org/platforms/armv8/generic

Some later discussion: https://news.ycombinator.com/item?id=47871519

So why is this important?