The tag is present in Lintian version 2.104.232. That is the most recent version we know about.
The package installs an upstart-job in
which is not registered in the
postinst script. On
non-upstart systems this is usually a bug, unless you omit the links
intentionally for some reason or create the links some other way.
This tag should only be emitted for vendors that do not use upstart by default (such as Debian). If this tag is emitted by a vendor using upstart (e.g. Ubuntu), it may be a misconfiguration of their Lintian vendor profile.