If you build it (the UCP), they (the guests) will come. Kinda.
Google UCP may be the door to a "post booking engine" industry, for both human and non-human bookers. More than a rupture, however, it formalizes a shift that is already underway. UCP, in fact, introduces a shared transactional language that allows AI agents, platforms, merchants, and payment providers to operate inside the same conversational space. Discovery, decision-making, checkout, and even post-purchase actions (such as leaving a review, requesting a change, or seeking support) can all happen within AI interfaces like Google AI Mode or Gemini, without forcing the user to jump between websites or apps.