When completing an in-place upgrade from 6.x to 6.3, sample content is installed on the instance. The runmode in the older AEM version was set to 'samplecontent'. Even when "-r nosamplecontent" is used when the upgrade is started, the runmode is not persisted.
When completing the inplace upgrade add --promote-runmode nosamplecontent to the command, for example:
java -Xmx4096m -XX:MaxPermSize=2048m -jar aem63-author-p4502.jar -v -x crx2oak -xargs -- --load-profile segment-fds --src-datastore=crx-quickstart/repository/datastore --promote-runmode nosamplecontent