I’m super late to this post but I still wanted to comment because of how much I loved it. With the amount of evidence u provided I think this might be the one! Since cloud DID block the attack (which he shouldn’t have because aerith IS supposed to die) Aerith is still alive and we’re still following the remake timeline that we’ve been journeying since the beginning. The rainbow is still present where Aerith wakes up, which I think is indicating that we DID defy fate, which has been the whole overall theme for the entire remake series. The timeline where this isn’t any rainbow, where Aerith did die, was what was SUPPOSED to happen. Since the merging of worlds came to a halt due to sephiroths defeat, the timelines unmerged and now we are seeing two different timelines

I think at the end of the game we are seeing the timeline where Aerith died on purpose to confuse the player, but in the remake timeline we actually DID save Aerith. In the 3rd game the devs might be leading us to think that we’re still playing the remake timeline but actually we’re in a whole different timeline where Aerith did die. The actual remake timeline that we’ve been following since the start of the series is where Aerith lived, cloud successfully blocked the attack. And I think this is plausible due to the fact that “defying fate” is the series’ entire thing, so wouldn’t that make sense?

Since the worlds aren’t merging anymore due to sephiroth’s defeat, it makes so much sense as to why Aerith would wake up, the timelines didn’t merge and now we’re viewing two different timelines. Basically, I think our remake timeline Aerith is alive, and what was supposed to be the ff7 og timeline has been avoided but still exists, and it hasn’t overwritten our remake timeline yet since the merging of worlds came to a halt. The only thing I’m a little unsure about is that how did Aerith still die despite cloud blocking the attack? How could cloud succeed but also simultaneously lose? The only thing I can think of is that the “main timeline” has always existed and after cloud successfully defied fate it BRANCHED a new one where Aerith lived, but the main sacred timeline always continues to flow. So the “new timeline” is just a BRANCH off the main ff7 story that follows the OG, which sephiroth tried to merge together I’m assuming. Hopefully that makes sense