You might want to restart services after they or libraries dependencies get updated. On debian based distros, updated packages automatically take care of restarting the service but it might not happen when only a dependency has been updated.

In the end it is easier to schedule a weekly reboot window if packages have been updated. You aren't running a single server if you are interested in 99.99999990% of uptime anyway.

Imho a regular reboot is good practice: you are more likely to remember what you did a week earlier if an app/service fail to restart after you tweaked a config file than if it happens months later.

There is no reason to be afraid of reboot when they happen on a regular basis.