It would be an amazing addition to be able to say "Hey Google, Report Left/Center/Right Lane Blocked" rather than needing to use the on-screen controls as it poses a safety hazard.

I feel as if that would entice users to use the feature more; it's a very beneficial tool to have, allowing you to prepare for the lane chance before it's too late.
That may also help with traffic congestion when everyone is trying to merge into a single lane on interstates.