In Ultimates #11 Thanos says, "Beautiful Death, to whom I once devoted my all. Perhaps somewhere, in the endless halls of being, some aspect of me is at her side..Content at last. Or perhaps THAT story, ended with the incursions." Possibly meaning that if the graphic novels happened, it was before the Secret Wars.
So I think that Ewing is a big continuity person and this is how he fit the OGN's in continuity!
You make good points. It's all a big jumble. Starlin doesn't really read current stuff and when he writes, he has to try and play catch-up. Marvel doesn't really make an effort to keep him abreast. I would say that we probably need to differentiate that which is in-continuity from that which is canon. Starlin's current work tends to be out of sync with continuity, but is officially canon.