Some configurations rely on the success of the two configurations CTL_ON_CREATE or CTL_ON_START.

Obviously some ejabberdctl cmds like register or status do not harm, if they aren't successful, but still a configuration may rely on them to be successful.

Others like join_cluster may be more problematic, as a configuration may rely on a successful cluster join, but ejabberd would only report an error, if it fails and continue being up. In this case a startup failure due to CTL_ON_CREATE or CTL_ON_START failure would at least trigger the attention on logging tools in regard of continuous restarts or whatever.