My gut says designers might be the ones creating the conversation scripts as time goes on. Reading the contexts and answering questions before the user really thinks about them is what makes truly magical design.
I also don’t think we will be in conversational UI for too long. There are more magical ways to get what you want done without the friction of a conversation. If conversational UI is here to stay I think it’ll be for a limited subset of use cases where it’s the BEST UI. After all, we still enjoy one button rides vs. calling a concierge.