Yeah but that was communicated in Archnews: https://archlinux.org/news/nvidia-590-driver-drops-pascal-support-main-packages-switch-to-open-kernel-modules/
Sure the Arch or package maintainers could provide migration scripts for stuff like that (there probably are rolling distros who do that?) or when they split packages but usually you are fine if you read the announcements and act accordingly.
One day I will figure out what other Arch users do and why my installation had not a single issue in the 3 years it has been running so far.
They did not replace repos, they exit in addition to the normal Arch repos, you can install any package from these repos if you want.
How does Cachy not work? How do you even use it in the same sentence as Manjaro? Cachy is just Arch + some optimized packages provided by their repos. You can theoretically migrate from pure Arch to Cachy by adding their repos and even the other way around.
Sorry that wasn’t meant like that, I was just pointing out that that was at least communicated in Archnews which not everything is, for example the firewalld package split you have to catch in the package update warnings which is easy to miss.