Adding NTP authentication to core and all distro/access switches. Will this cause service disruption?

Layout: Core gets time from industrial GPS clock. Core is set up as NTP server, and all lower level switches get time via core IP address.

There is currently no authentication / key on NTP.

If i do this in the day, will it cause connections to drop? There are all static routes. Im assuming the only trouble i will get, will probably witb the remote syslog server?

Core switch: Ntp authenticate Ntp authentication key XXX Ntp-trusted key 1 Ntp server 192.168.100.100

All other switches using CORE as NTP server Ntp authenticate Ntp authentication key XXX Ntp-trusted key 1 Ntp server 192.168.100.200

Thanks