The current plan is to continue with provisioning OVAB using Oracle Installer but we will surely make a note of providing an OVM template for OVAB in future. At the same time, would be interested in knowing your use case where you think an OVM template would be much more useful/easier than using Installer to provision OVAB product.
I provision a lot of virtual machines on Oracle VM Manager. I wanted to use OVAB, so automatically looked for an Oracle VM Template to save me doing all the OS + product install myself. It would make it so much easier for me to get up and running as my environment to deploy OVAB is Oracle VM.