In lack of a <reporting>/<pluginManagement> section in the POM, one cannot configure things like issueLinkTemplate in a central place but has to do it over and over again in each project. If the plugin would support properties, one could simply put

<properties>
  <changes.issueLinkTemplate>yadayada</changes.issueLinkTemplate>
</properties>

into the corporate parent POM and is done.