Hmm sounds reasonable. After my question I was reading the original news from Archlinux and the following statement

In order to not break user setups, we kept these repositories around in an unused and empty state.

suggest that the empty and unused repositories have no effect. I don’t know why they kept this, because removing them would break back then. Removing them now breaks it today, so not sure why they delayed that, as nothing is won. I will uncomment out (Edit: I meant I will comment out) those lines and see what happens. :D In worst case the system cannot update and I can reverse the change. But there is no reason why the system should not able to update, if the repositories are empty.

Another Edit: Me dummy don’t have any [community] repository. Not sure if I removed it before (very possible) or if it is removed by my distribution (please don’t hurt me, I’m just using EndeavourOS).