This is for rpm-4.13.0.1-5.4.x86_64 on Tumbleweed 2017-09-05,
systemd-233-1.1.x86_64 .

/usr/lib/systemd/system/rpmconfigcheck.service does not run at boot
time.  It is WantedBy default.target, and (on most systems including mine) 
/usr/lib/systemd/system/default.target is a symlink to graphical.target.
Links in /etc/systemd/system/graphical.target.wants are obeyed, but
links in /etc/systemd/system/default.target.wants are ignored.  

Workaround: Copy to /etc/systemd/system/rpmconfigcheck.service and change:
[Install]
WantedBy=graphical.target
WantedBy=multi-user.target

Maybe a better workaround is to make default.target a separate unit that
Requires graphical.target (or multi-user.target, on servers).  I think it's
valuable to make a unit WantedBy default.target versus enumerating all the
toplevel runlevels, when the sysadmin could create a special runlevel on
a special purpose system, that SuSE units would not know about.  

Another issue: the unit lacks RemainAfterExit=true, so my system
integrity script thinks it died, reports it to the sysadmin, and
restarts it.  I don't know if SuSE has a policy about this, but I would
suggest that if a service started at boot is found dead, that should be
considered to be an anomaly that needs to be dealt with.

OpenSuSE "Leap" 42.1 has services systemd-readahead-collect.service and
systemd-readahead-replay.service which are WantedBy default.target and
hence don't start at boot.  But they do have RemainAfterExit=true.