start_pms was removed because /etc/init.d/plexmediaserver was completed to fully contain all the functionality of /usr/sbin/start_pms. That made start_pms which was previously called by /etc/init.d/plexmediaserver redundant and no longer needed.
If you wish to have /usr/sbin/start_pms, all you need do is create it to call /etc/init.d/plexmediaserver start and launch PMS as the service it should be.
It will use all the same values from /etc/default/plexmediaserver
Discussion thread is here:
We did find one timing issue with it which I’ve corrected and is coming as a hotfix.
