I asked my rep the same question and this is what he responded:
“I was advised by my Sr Rep that the migration from legacy Endpoint Protection AV to Avast new Business AV is simply an 'uninstall/re-install procedure.”
Yup - rip it all out and start from scratch. Nine sites, over 200 nodes.
A few weeks ago we published a public roadmap where you can see what features we currently have in development for the new console. If you check it you can see that we are currently developing migration paths and tools for devices managed by Small Office Administration and Avast Enterprise Administration consoles. You can also submit ideas or vote for us to prioritize specific development tasks.