Very interesting way to look at it.
It’s similar to how I interpret the disturbance in the force from TESB. I see it as when Luke, after 3 or so years of doing as best as he could with the minimal instruction he’d been given, finally achieved a massive checkpoint when he was in the cave. That being that he, when in a situation of extreme danger, concentrated and focused, and ‘calmly’ used the force, which is absolutely a trait of the light side of the force and something that Ben tried to teach him, and that Yoda emphasizes.
Back to the ST, I can see the boy from Canto Bight supporting a direct opposing argument to the one I made. But the one you’re making is hard to argue against due to simply being something very hard to demonstrate on screen without losing focus of a film. Still, the question should be, do you think that this ‘pent up force potential’ is still around, or that it is now all concentrated on Rey and she’s the sole hero? I think that’s essentially what would show if she’s Rey Random in one way or in another, or even not at all, like DrDre and Anchorhead argued.