Pretty good summary but as an unofficially certified lorehead just a couple things I want to correct 
This is a mix of the older lore and the new lore, in the new lore Prometheus never outright overthrows Zeus to become king of the gods. What happens is that Zeus gets fed up with humanity having magic a hundred years or so after Prometheus gives it, so he starts taking it from people. This causes Prometheus to oppose him and the starts the War of the Gods with .
The lore doc doesn’t even mention Prometheus killing Zeus anymore, but I’m guessing he has to at some point in the war, which probably turns the tables in favor of Prometheus’ side. Then that’s when Arthur does his thing.
While we do unfortunately have confirmation that Theos is British, we don’t actually have hard confirmation that Theos is a legacy, unless I missed a new Vetex statement. What Vetex has said is that Theos was a “regular” human that was special in the same way the AO MC is, which he calls spoilers:
Considering the AO MC being a legacy has been in the story for 2 years (I think), I doubt that would be the spoilery special trait. Plus Vetex outright calls Theos a regular human. And unless Theos was gonna somehow be in the AO story then idk why confirming him as a legacy would be spoilers, but I guess he could be involved in the story as a historical thing?
So either you’re right and Vetex is trying to keep Theos being a legacy under wraps (despite calling him a regular human), or Theos and the AO MC have something else special about them that’s not being a descendant of a god. But again, no hard confirmation that I’m aware of
erm achktually Acheron finds the Absorption blessing in Y1015, 800 years after the ending of the war of the gods in Y227. rookie mistake to not have every single date on the lore doc memorized smh my head