For packages-distro.conf, the leanest display manager (either Xorg or Wayland) that is included in the official repo for the given distro would be included. For instance for Arch Linux, this would be 'slim', even though there are slimmer display managers like 'ly', 'tbsm', 'cdm' etc. but unfortunately there are in AUR at the time of writing this document.
Arch's pacman package manager sometimes requires a refresh of the PGP keys