That is to say, I’ve got reflector running as a daemon on my vanilla Arch machine and EOS has their mirrorlist update tool as well. In both cases, they’re going to grab the latest mirror data, rank order them for me, and update my mirrorlist accordingly. On the other hand, mirrorlist.pacnew is just a commented out list of the latest available servers that I could also get from the Arch website if I really wanted to know what they were.
So, I really should be able to uncomment “NoExtract” in my pacman.conf file and add /etc/pacman.d/mirrorlist.pacnew to it. That is; “NoExtract=/etc/pacman.d/mirrorlist.pacnew”. Not that mirrorlist.pacnew does any harm being there, it just avoids the warning message when it updates.
Basically, as long as your mirrorlists work, you don’t need to change them.
However, there are cases when some of the mirrors will be either temporarily or permanently disabled. If that happens to the mirrors on your lists, then you may need to use reflector or eos-rankmirrors again, or manually re-order the lists.
When you get these files, there an app in the welcome center to help you see the difference in the old file and new file.
If you like the old one then remove the new one. If you’d like the new one, then replace the old one. If you want to merge the new bits into the old one merge them save and then remove the other.