Well, now it's my turn I guess to be such an old grognard that I think D&D has gotten drunk and weird. And additionally, "There are the gods and their allies vs the enemies of the gods." is just flat out dumb, and I don't think you could make that coherent with D&D's usual polytheistic constructs and half a dozen of D&D's other assumptions.
That's basically it.The Greek Pantheon and the Titans would like a word.
4e's Dawn War is just the Titanomachy and Aesir-Giants war without them being related. People actually liked it and DMs released that it was easier to make sense of.
New gods banish or kill old gods. Newer beings like fiends fight to replace gods or tear down the system.