In lore has Annam ever returned in previous editions/stories

I am working on a campaign setting idea where Annam returns and then triggers a series of cataclysmic events.

Much of my inspiration for this is the initiation of Ghehenna in the world of darkness series and there is a strong possibility my campaign setting will be brought to a total end, or at least be forever changed.

My question is, in the history of DnD and the many published stories, adventures and campaign settings defined has the potential/actual return of the God of giants, and what the potential outcomes of it could be?