Fraud means a deception for the purpose of financial gain, so I think as long as they're not selling these while giving the impression that this is autonomous behavior, it's not fraud.
In any case, from the article,
"Another robot — or the human voicing it — told an attendee in a stilted impression of a synthetic voice, “Today, I am assisted by a human,” adding that it’s not fully autonomous."
So it seems in fact they were fairly transparent about what was going on. The article just has a deceptive headline.
Maybe, as always, they were trying to juice the stock price with this promotional event, but if the robot is telling people that it's controlled by a human, where is the lie?
In any case, from the article,
"Another robot — or the human voicing it — told an attendee in a stilted impression of a synthetic voice, “Today, I am assisted by a human,” adding that it’s not fully autonomous."
So it seems in fact they were fairly transparent about what was going on. The article just has a deceptive headline.