I expect a game that is more than just Lumiose City, much like PLA was more than just Jubilife Village.
I expect it to be post-XY, despite everyone decrying it to the contrary because one not-actually a-renovation, supposedly fits the games description of renovating Lumiose into a town for both Pokémon and people.
That we get an underground area we can explore, abandoned subway tunnels leading into natural or artificial cavern system beneath Lumiose, that ends up revealing that more life exists below the surface of an urban city than we may realize.
That Snivy, Litten, and Totodile are the starters,
That Terastal Crystals appear beneath Lumiose because the big bad ends up replicating the success of Blueberry Academy’s work to bring Terastalization and the threat of Paradox Pokemon to more than just Paldea. New Paradox Pokémon as a result.