I loved the ending. I mean granted, I'm probably one of the biggest Kingdom Hearts fans on the planet... But I like it a lot.
I also have a sneaking suspicion that what we're seeing isn't necessarily what we think it is. Much to think about, and I'll make a theory-post on it shortly.
I'll say this though. Considering how well Square made the Remake, and then changed it up in the last hour or so... They're ballsy. They know exactly how people would take a change like this, so the question is... Why? They're not fools over there (at least, that's what I believe). I've got some ideas, but oh man. Much to think about, much to discuss.
I think the why is the ability to take more creative liberties and make more games and more money, but the execution turned out pretty solid so people won't see it that way I don't think.
Its not quite Kingdom Hearts level bullshyt... but its definitely further off the rails than Xenosaga or a Metal Gear Solid which is saying a lot.
But without ruining your experience with OG and the other stuff, Sephiroth basically was okay with 'dying' but not losing completely. This is alternate universe that's been altered in more ways than one.
The overall implications are wild but it doesn't necessarily change any existing works because they're already done. What happened still happened, but characters have those flashback or memories as a sort of reference in some ways and Seph (as well as Aeris who's clearly not showing her complete hand.... she is out here handing out visions to Marlene and Red of all people) is using it as a playbook to push people in certain directions. I'd be upset if they didn't do a great job across the board with everything outside of the heavyhandedness of the plotghosts
I actually didn't even think about the fact that Aerith probably knows what's going on already, I was thinking only Cloud was seeing stuff since he gets the flashbacks, but that's a good point. So there's probably at least 4 characters that can be aware that there's a different timeline that already happened, Cloud, Sephiroth, Aerith, Red (I don't think Marlene will end up knowing what's actually going on.)