System update removed rt_tables

During a system update on a pc that had not been used for about 12 weeks, the file /etc/iproute2/rt_tables got removed. I assume this was caused by the update to iproute2 version
I mention this here so that if anyone who are using custom routing tables experiences strange network behavior after update, checking that the routing tables still exists might save some time debugging.

debugging what condition?

The file is still present here.

The /etc/iproute2/ directory is no longer part of the iproute2 package. Arch removed the backup() array three months ago with 6.5.0-1. I have not reviewed upstream changes as to why that occured. You should have a pacsave for any files in that directory.