cq:template=/libs/fd/af/templates/blankTemplate2 were used till AEM Forms 6.3 and they are older/static templates. Starting from AEM Forms 6.4, dynamic templates are now used. These are similar to AEM Sites templates. You can find details at the below article:https://helpx.adobe.com/in/experience-ma...

Here is a documentation which talks about "Migrating from Flex Workspace to AEM Forms workspace" as well as "HTML rendering of XDP Forms". [0]: https://helpx.adobe.com/in/experience-manager/6-4/forms/using/html-workspace-overview.html