I understand where the premise of the Finale came from. But I don't think the plot concludes the narrative arc well as a message.
I understand that the narrative chose to use these specific lines.
"God does not play dice with the universe; plays an ineffable game of own devising, which might be compared, from the perspective of any of the other players [i.e. everybody], to being involved in an obscure and complex variant of poker in a pitch-dark room, with blank cards, for infinite stakes, with a Dealer who won't tell you the rules, and who smiles all the time" - GOOD OMENS BOOK
and
"Maybe it's all part of a great big ineffable plan. All of it. You, me, everything. Some great big test to see if what you've built all works properly, eh? You start thinking: it can't be a great cosmic game of chess, it has to be just very complicated Solitaire". - GOOD OMENS BOOK
The plot itself says that God placed Satan as opponent so would have someone to play with. He's nothing more than a pawn too!
And, remember, Solitaire is a one-on-one game!
How to solve it? It's difficult!
The finale was an attempt to directly answer the central dramatic question: how could people continue in a system that was a game for God (and is, since the book), how to solve this problem?
The realization of this has an impact Crowley; and it makes them, he and Aziraphale, choose a new universe, in an attempt to overcome the one where they were created and in which they were nothing more than pawns.
I understand the Finale narratively, in this respect. But many things remain open; is the new universe really what they asked for? And if it isn't?
Are they or are they not Asa and Anthony? If they are, what are the implications? If they aren't, what is the explanation for so much similarity? They didn't want anything ineffable for that new universe, but isn't everything that happens in the new universe already ineffable enough?
In the END, God caught them alone. The world was already destroyed when they were allowed to ask 'the questions' and 'reach a decision'; they had no one left to fight with them against God, and accepting God's idea of putting everything back in the same place doesn't seem very sensible after all.
But a new universe, I'm not sure if it was the right decision either, especially since we don't know if it was a bluff by God (as it seems it was).
I find myself thinking that a Tolkien-style ending, where the immortals had to leave Earth, would be better as a 'final decision'.
Instead of Crowley and Aziraphale, it could be Adam and Josh/Jesus at the end facing God, asking for the world back, but everything supernatural, angels, demons, heaven, hell, God and Satan, would need to stay away. At most, they could observe from afar, without interfering… those who wanted to stay and interfere could simply stay, but as humans, and all the laws governing the universe from then on would be the laws of physics and nothing more.
So Aziraphale and Crowley could choose to stay, or not. And they could talk about their feelings and their actions, keeping their memories, they could decide whether or not to be a couple.
They would decide about the bookshop and the Bentley, and whether or not they would go to South Downs!
The ending that the plot officially could have been MUCH different. I think we all wanted it to be different!
The problem is that since the second season, remove the humans from the focus (S2 simply ignored all the other humans from season 1, Anathema, Newt, Tracy, EVERYONE), and put Crowley and Aziraphale as protagonists. A fatal flaw in the plot, it seems.
But then I remember Agnes Nutter's prophecies…
"Further Nife and Accurate Prophecies of Agnes Nutter," Anathema read slowly, "Concerning the World that Is To Come; Ye Saga Continuef l Oh, my . . .". - GooD Omens Book.
And I keep wondering if… this new world we see is about that on Finale.
In any case, I was left with the feeling that God won! Yep, without heaven and hell, ok, it's no longer playing cosmic chess, but this is still Solitaire, isn't it?
God is playing Solitaire and everyone continues to be her playing cards?
It doesn't sound encouraging at all as a message.
Whatever God is playing, it's still a game in the end… how can I be positive about it? Trying to reconcile myself with this idea, but it's difficult.
I'm glad that humans still exist and, apparently, are happy in the new world, including the new versions of Aziraphale and Crowley, but I'm concerned about the implications of what this new world/universe represents.
The question of whether God is still playing or not remains open, according to that finale on screen.