After AEM migration from 5.6.1 to 6.2 I realized that node /etc/tags was missing. After migration procedure step-by-step check it was found that it was 6.2.0 hotfix 12785 version 7 that removed /etc/tags node.
Is there any change in AEM 6.2 related to tag node location? Is this behavior expected? In our case original content was restored from production and everything seems to be fine.