Assuming Aziraphale has zero idea that Second Coming involves torturing demons…
This is what is going to make him snap, is it not. I mean imagine you go to Heaven really hoping to fix it and you find out that Second Coming not only means end of the world (he knew about that six thousand years ago) but torturing fallen angels.
Imagine his face when he realises that they’re planning to do that to Crowley.
What does he do? He runs to Metatron? He showed him that Crowley can be an Angel again so obviously he won’t be treated like other demons, right?
But Metatron has everything he wants now so he doesn’t need to lie to Aziraphale anymore. No, Crowley made his choice, he stayed with demons so he will be treated as one.
But, but, he can convince him! He will try again!
No, too late for that.
What if Crowley will already be captured? Metatron clearly can’t stand him.
Or will he tell Aziraphale he can try again? Knowing Crowley still won’t come back.
But imagine Aziraphale grabbing Crowley and nervously telling him that he has to come with him or they will hurt him. Crowley still won’t go. He will look at him in even bigger disbelief. You are still on their side? Come to Heaven? When they just told you they will torture me otherwise?
I can imagine Aziraphale finally stopping, forced to face the truth.
Or if he found out they captured Crowley? After telling him he can totally be an Angel again? Realising they lied about everything to him and now Crowley will get hurt?
Oh boy.