This is a seemingly simple addition, but it's arguably crucial. Much like the alerts you receive when you have an upcoming bill or need to leave for a meeting, it's surfacing info at a relevant time to help you make informed decisions. It also helps Google (Android in particular) stand out among internet rivals that don't necessarily have its tight integration between AI, search and mobile apps.
Google said it would launch proactive warnings of flight delays through Google Assistant so travellers could check last-minute problems. It already offered fight delay information but only for travellers who searched for a specific flight.