To be honest, I am actually hoping for some kind of Reach (game) reference in the book, such as the fall of New Alexandria, or Halsey commenting on the structure under Sword Base.
IIRC, Lore wise we have been to Reach after the Fall, in First Strike for instance. But in terms of Reach related content that has been released, I think the game might be the last time we were there.
Now that the game has given new details to various conflicts and engagements that took place during the Fall, it would only make sense for them to reference them. Maybe even a wee explanation as to how the invasion was kept under wraps for so long?
I wouldn’t mind a nod to Noble 6, like Chief acknowledging that he was aware of the other Spartan.
Anything more would have the potential to bring the ‘cult of survival’ out of the woodwork, and we’d see a flood of new non-constructive posts, and people begging 343 to put 6 in Infinite.