New util-linux provides all rfkill includes, making rfkill obsolete (thus rfkill will be removed from the repos). This was missed during the update to util-linux-2.31. Corrected version is now up, save to install with:
sudo pacman -U http://kaosx.tk/repo/build/util-linux-2.31-2-x86_64.pkg.tar.xz
After this, update will continue as should. This rebuild of util-linux will move to all users asap.