I looked through the Google Home developer info, and it looks like it will definitely be possible to add ISY integration if UD wants to do it. On the downside, for now we may be stuck with a round-about way of saying things like "hey google tell isy to turn the lights on". Info on that here: https://developers.google.com/actions/distribute/invocation-and-discovery
But there is hope that if UD is approved by Google, Google may eventually approve them as a "direct" action. More info on that here: https://developers.google.com/actions/develop/direct
Hopefully UD has already submitted the form to ask Google to approve them as a direct action?