I say this because I see that Lillie starts out these games in her Nihilego-lookalike look *again* as footage from the most recent trailer shows, and seems to be inferred that she goes through the same Z-Powered Lillie development *again*, the twist I guess with these games being that she's more than tolerant of Pokémon battling. If these were sequels to Sun & Moon, there'd be no reason to ever relive that moment of confidence boost, if we've ever learned anything about her mother's past transgressions with her. I would _love_ if, had these continued the story, that the thing with Lusamine going into rehab from all of... that, was resolved, and the thing with Mohn was "figured out" somehow and reunited the family. I just know that he's gonna have a role in the plot in USUM this time, but I have doubts that it's anything crucial.
Progression in time would've helped, for instance, to build up that one guy's plans to make a Fossil Pokémon Jurassic Park a reality by actually being able to visit it in these games, if these were sequels. Not that it couldn't become a new location introduced in USUM, but by being an alternative-retelling-whatever, it makes a little less sense.