It's interesting how past experiences influence what people take a way from comments.
I see "the overarching story follows the original" and see... 95% of all Time-Travel Fan-Fics in there. Particularly the trope
The Stations of Canon. Which is... essentially the idea that even with changes to the source material happening, the vast bulk of the story events do happen in some size, shape or form. The story *has* to have certain events happen so that it can be recognized as that story. Of course... how the events *happen* can end up wildly different. But it's still following the overarching story of the derivative work.
It's honestly really funny looking at the FFVII Fan-Fic "Stations of Canon" entry, because the Midgar Section of it sounds so much like what we got in Remake.Like... that's the story of... 90% of rewrites of FFVII. Time-Travel, Zack Survies, Cloud doesn't loose his memory, Vincent wakes up early, Cloud gets into SOLDIER, the list goes on... Most of them will hit all the main story beats of FFVII and tweak the events a tad, but the events still happen (you should see how many variants of Nibelheim Incident people can come up with in CC era fics!).
What *does* change is the tone and theme of the work a lot of the time. Sure, the *events* are still happening, but the story does end up feeling different if Zack is around, or Cloud gets his head in order early or half a dozen other things. Or you know... when we've killed Fate and have an Unknown Journey ahead of us...
I've just seen so many ways of still having canon events happen for very different reasons by this point that... the overall events of FFVII kinda... I wouldn't say they've lost their meaning. But they're definetly more like set-pieces. The event itseslf isn't the important thing I pay attention to. It's all the ways that event is different than how it happened in canon that I notice. That's what most fan-fics want to show off: how a few changes can snowball across all the events we're familiar with.