Azem knew we would come back to help Elidibus. I mean it's almost certain that they had either knowledge of the future, be it prediction or any other time shenanigan.

We also know that, from their character, there is no way they would have accepted the Apocalypse if they knew there was a way to stop it and I refuse to accept they just did nothing and waited for the end.

I'm convinced the big reveal of 8.0 or maybe later is that they knew it all and prepared for the Withering as everyone else thought they just gave up or simply disappeared.