I'd argue that its a very, very tiny portion of the Halo 4 playerbase that hase read the Halo 3 terminals (and understood them), much less read them, understood them, and have kept up with the latest novels.
Its one thing to have novels and cinematic shorts outside of the game provide more depth and background, its an entirely different thing to require them to have any sense of WTF is going on and why. That's the problem, and that's where 343 dropped the ball big time.
The average playerbase probably doesn't care much more about who
the Didact
the Librarian
It might have been helpful to let Halo 4 players know thatthe humans being referred to here are not the humans we know, but an entirely separate humanity that arose, explored space, fought the flood and forerunner, got devolved by the forerunner, and then got wiped out entirely by the firing of the rings before re-emerging on Earth thanks to the Librarians indexing program. Yeah, that would've helped quite a bit don't you think?
Yes absolutely, but it was still stated that they were
ancient humans
More elaboration would always be welcome, I'd never argue against that. But I do believe that enough was given to understand the story. For those looking to delve deeper, there are avenues for it. It's certainly not required.