Aaaaaand you just resurrected a theory.
I think there's been alot of teasing and hint-dropping that in the end, Gracie's going to be the villain. Or if not THE villain, then at least a villain.
Note that doesn't necessarily mean that things won't end amicably and reconciled. Plenty of villains get redemption arcs. But ever since I realized Gracie's a psychopath I started to suspect she was gonna end up an antagonist. It was reinforced when even Cordia showed signs of being worried about what Gracie could become if she were ever taken off the leash.
My suspicions were further enforced in that whole flashback scene where Gracie has the pacifier....showing how cold-bloodedly manipulative she was even then. Then that is followed by MC theorizing what would happen if Gracie and Luna ever became enemies...I think Uncle doth protest too much in that scene.
Heck upon revisiting it...that scene is even named "Portend" in the replay section. Crack out your dictionary and look up the definition of that word people. lol.
But I dismissed this theory a loooooong time ago cuz I assumed that after all this time the game's probably approaching it's conclusion and there isn't enough time to write a villain arc for Gracie, let alone a villain/redemption arc for her.
But if this is only season 1....
Well, I wouldn't outright dismiss your theory (unless Hopes says "Nope, that won't happen" [but even if it happens that way, it's pretty much deep in spoiler territory, and I'd assume he'll keep it close to his chest]), but going that route with Gracie presents two issues;
1) Making her an antagonist would most likely put a stop to her freeroam/lewd events section, so unless Hopes is preparing to do that for Gracie's character (or all girls freeroam/lewd for that matter) it likely wouldn't be a good idea.
as well as;
2) Making Gracie an antagonist I don't think would be met with a positive reaction from Gracie fans.
I mean, I'd only consider Gracie to be my third favorite girl (my favorites go in order of Luna, then Cordia, then Gracie/Isabel), but over the years I've seen quite a considerable number of Gracie fans out there.
They may not be as big as Luna's or as loud as Cordia's fandom, but they certainly exist when they wish to voice their love for her character.
Hence such action might have more of an adverse effect on the game than it being a boon (especially if Gracie is the player's favorite girl).
Portend despite the definition of the word, I think it might be one of those rare instances where the event title may be a red herring.
Plus, there's the MC's inner monologue at the end of that event:
"As much fun it is to think about (Luna vs Gracie), for it to happen for real is another thing. I would never let that happen. I'll protect both of them."
He's made a solemn promise to himself there that he will not let any conflict get in between the DeLuca sisters (2 of the most important people to him), and Gracie becoming an antagonist basically would mean that he has failed to keep that promise. Not sure that would be something I'd be too keen on seeing.