Seen on infra.opensuse.org machines after upgrade from Leap to Tumbleweed:

nrpe is using %service_add_* macros, they enable nrpe unconditionally if a new
service file is added, independent of, if nrpe was somehow enabled before or
not.

On the infra machines xinetd is used to start nrpe, so you always get errors
during the boot process, either from xinetd or nrpre.service, depending on
which ones runs faster or get's restarted during update.

I don't think nrpe should enable itself unconditionally during an upgrade.