>Opening credits and cutscene
>Starter selection and rival/friend battle
>Explore town and talk about new/returning features (e.g. bar area, customization, respectively)
>Start exploring on journey
>Run into bird, koala, and dog since they're the early route mons (like Starly/Bidoof/Shinx)
>Officially reveal those 3

What do you expect beyond this? This point is where everything we've seen so far would be accounted for. Zygarde could potentially be part of it, but I'm more inclined to believe that stuff is more post-game, or late-game if Zygarde ties directly into the plot.