Here's a GO meta nobody cares about anymore.
Remember all the theories about the small discrepancies in s2? A disappearing prop here and there, Crowley's different sideburns length. Funnily enough, it happens at the beginning of GO3 - we see Crowley sleeping on top of his sleeping bag, but when he rolls to his side, his legs are inside it.
Not that we ever got any pay-off for noticing. The only thing that could act as an explanation are Michael's words:
"The Metatron did it first. He used to just fiddle with things in the Book, get them how he wanted them."
So what if the discrepancies in s2 were the Metatron "getting thing how he wanted them"? He was making consecutive edits until he achieved his goal.
Picture this:
Take 1:
The Metatron: Gabriel, you have failed your duties, I hereby sentence you to fall!
Gabriel: Aw, shucks. Tough luck, I guess!
[in hell]
Beelzebub: Damn it, Gabe, who's going to stop the Second Coming now??
Gabriel: I may have an idea.
[Whickber St, a knock on the bookshop door]
G&B: Hey guys, how do you feel about doing a little project together?
Take 2:
The Metatron: Gabriel, you have failed your duties, I hereby demote you!
Gabriel: Well shit!
[later]
Jesus: This is all very confusing, can I maybe talk to that cool yellow-eyed entity I met last time?
Sandalphon or someone: You cannot. He's on Earth. Not our kind of person.
[Whickber St, a knock on the bookshop door]
Jesus: Oh, hello, consensually co-inhabiting eldritch entities! I was looking for a friend of mine... Oh, there you are! Could you advise me how I should go about destroying all humanity?
...And so the Metatron keeps changing and adding things. Eventually, he realises the only way to stop Aziraphale and Crowley is to get Azirapale back to heaven. We get to an iteration of the Final Fifteen, but I imagine Aziraphale chooses Crowley, and keeps choosing Crowley no matter what the Metatron changes. Or maybe Crowley agrees to tag along, and that's why the Metatron later adds "restored to full angelic status" knowing that would be a dealbreaker.
And while we're at it, perhaps the recasts (Maggie, Nina, Furfur and Shax) are his edits as well? It was aiding Maggie and Nina's romance which made Aziraphale organise the ball that later led to the siege organised by Shax.
It also explains why Crowley doesn't remember Furfur - his brain hasn't caught up with the edited reality. Remember the "two of them were wrong" theory? For those who don't know it - in the novel it's said that people assumed Aziraphale was intelligent, English and gay, and only the first of those things was correct. Some fans noticed that in the minisodes Aziraphale is called brilliant (Uz), English (Resurrectionists) and gay (1941), so if you draw a parallel, only the first minisode was true. Could the other two have been the Metatron's edits? Both show to Aziraphale how much Crowley is risking, how big a threat he's facing (and, Furfur, our last recast is instrumental in 1941). And let's all agree to ignore all the superficial explanations he gives in GO3 - he is horrified after talking to the Metatron in the Final Fifteen! These things, along with many other factors (being exhausted post-siege, robbed of his romantic night at the ball with Crowley, perked on coffeine and sugar) and Crowley hyperfixating on his own confession at the time (thanks to our two other recasts!) lead to the outcome we see in s2.
As I said, at this point with the incompetent disaster of GO3, this is all pretty worthless. But it's nice to imagine Aziraphale had been averting the Second Coming and choosing Crowley over and over, forcing the Metatron to make countless edits and additions to BoL before he finally got it his way (and even then - remember how reluctant and close to changing his mind Aziraphale was?).
On a final, equally useless note. If we accept this theory, the sleeping bag tells us by the start of GO3 the Metatron is still editing. His efforts are cut short by Michael's actions (which in itself is ironical, as this is what finally brings about the planned distruction of the universe he was striving for). This would mean that what we are shown is a version. And at least the second one after Aziraphale becomes the Supreme Archangel. It's frustrating we won't get any more versions after this, we'll never know what the original version was (isn't that meta in a completely different way!).
But perhaps this is all just me still wallowing in denial and desperately bargaining to spot anything salvageable in the debris of this catastrophe.