My guess is that Valve will keep their own mirrors and update from upstream only once their relevant packages will be tested for compatibility. I have been usi

My guess is that Valve will keep their own mirrors and update from upstream only once their relevant packages will be tested for compatibility. I have been using Archlinux for more than 10 years and from time to time some major upgrades can make things broken for a couple days until all the packages get updated and all the relevant compatibility fixes have been pushed upstream by the developers. But in most cases this happens with some 3rd party desktop related packages or closed source drivers. I bet that Valve won't have that many problems with AMD since their drivers are open source.