That's my read/thought too. The generator is lost, and distributions will probably be carrying an analogue forward -- for benefit of third party relics.

I don't believe it makes much more assumption than... $script {start,stop,restart} as the Exec lines in the unit

The hairy part is how package scriptlets and so on that assume SysV... want old utilities -- eg: chkconfig, service.

systemd captured these, and that may go away too