Pretty much everyone was flabbergasted about how natural the calls sound, although you won't be listening them as Assistant does this in the background, but many were also puzzled whether this might have ethical consequences.
Should the recipient know that he or she is not talking to a human? With all the "umms" and "mmhmms" Google Assistant had seemed to passed the Turing test in demo calls played back at the I/O stage.
And now, in an interview with CNET, Google agrees. Agrees not only that Turing test might have been passed but that it is necessary to make sure the receiving end of the call is aware that they are talking to a robot.
Currently it is not known how this will be implemented, even though Google does say that they've been anticipating this criticism or concern. One would imagine that a disclaimer in the beginning might result in large portion of the calls being hung up.
It remains to be seen how Google tackles this ethical quandary. It's a good thing Siri can barely tell you the weather.