I agree and disagree with you here.
I agree in the sense that Intercom and Drift have proved that real time messaging can play a crucial role in lead qualification. Heck, HubSpot has invested in Drift!
I disagree in the sense that there is still a important distinction between an automated solution and a human-in-the-loop interaction. Proving that a fully automated conversational interface works better at lead-gen than a graphical interface is much harder.
(Operator, although interesting, is still not there in my opinion. It is basically a re-bundle of existing features)