The above is for running Jenkins in Tomcat, isn't it? It also seems to be RedHat specific (/etc/sysconfig). When running apps in Tomcat, one usually just need to start Tomcat itself, which in turn takes care of starting all the webapps deployed to it. So setting up a "tomcat@.service" for single webapps doesn't seem to be necessary at all (and also feels wrong given that this would mean to start one Tomcat instance for each webapp configured this way).
OTOH, this ticket is about a "native" systemd unit, which I think means: One that starts Jenkins standalone, just like the current sys-v init script does.