Hi Guus,
That said, it's still a good idea to restart the running services (or the whole server when the kernel is updated), but in principle you can just continue working while updating and reboot sometime later.
IIRC, some other distros re-start a server as part of the package-upgrade process, including if a configuration file or a dynamically-loaded library used by the server from another package has been re-written. It was a surprise to me on moving to Arch that it didn't. I've a little ~/bin/oldpkg which I run after an Arch upgrade to help eyeball those servers which are using now-deleted files which I think have been replaced during the upgrade. sudo lsof -n +c0 | sed -n '1{p;d}; /DEL/{p;d}; / (deleted)$/{p;d}' | egrep -v ' /(run/systemd/(inhibit|sessions)/[0-9]+\.ref|SYSV00000000|dev/shm/org\.(chromium\.......|mozilla\.ipc\.[0-9]+\.[0-9]+)|memfd:pulseaudio|tmp/#[0-9]{5,7})\>' | sed '1{h; d}; 2{x; G}' -- Cheers, Ralph.