Currently syslogd(8) doesn't reload its config files when they change.
Reasons for the change:
1. When new packages are installed and place new config files, these files aren't automatically enabled which can always be used as an argument against even using such config files, like it was done in this bug: bug#232813.
2. newsyslog(8) does automatically reload its configuration when it changes, but syslogd(8) doesn't, which isn't logical because they work in the same field (manage logs).
So it appears that it would be much more natural and convenient if syslog(8) would auto-load/unload config files when they are added/installed/uninstalled.
(In reply to Yuri Victorovich from comment #0)
newsyslog doesn't "reload" its config files, it loads them every time it runs. It is run every hours by default.
You're right that there is a discrepancy between newsyslog and syslogd there though.
But most daemons do not reload their config files automatically and doing so would break expectations I would say. cron is a notable exception.