They still want people to stick around and 'bond' for lack of a better term with their particular style of chat bot. Like so many venture funded money pits of old the cash burn now is about customer acquisition while they develop and improve their tech. They're all racing toward a cliff hoping to either make the jump to the stratosphere and start turning massive profits or to fall off and splat on the rocks of bankruptcy. If they don't get the engagement loop right now they won't have the customers if the tech and use case catch up with the hype and you can only tweak these models so much after they're created so they have to refine the engagement hooks now along side the core tech.