Where did you get this notion?
343 literally requires their books to be read in order to understand what is going on in the Halo Franchise.
Which is quite obnoxious.
Bungie’s books were just extra-lore snippets so you had optional stories to expand the universe.
Meanwhile the majority of 343’s books are required to understand the narrative of their games.
This is because Bungie’s games take place within less than a year’s timeframe.
Halo Reach starts on July 24th, 2552 and Halo 3 ends on March 3rd, 2553
5 games pretty much back-to-back.
Meanwhile Halo 4 takes place in 2556, Halo 5 in 2558, and Halo Infinite in 2560.
TWO YEAR GAP BETWEEN EACH GAME.
So the books now fill in those gaps and most of these novels and comics are now required in order to understand what is going on.
Who is Vale? Read Halo: Hunters in the Dark.
Who is Tanaka? Read all 24 issues of Halo: Escalation to find out.
Who are Fred, Kelly, and Linda? Read Halo: The Fall of Reach, The Flood, First Strike, Ghosts of Onyx, Glasslands, Last Light, and Halo Escalation to find out who they are and what they mean to John.
The transmedia (yes that is the actual term as the media is not on one singular platform) is all over the place.
Imagine jumping from Episode 7 to Episode 8 of a TV series and all of a sudden NOTHING makes any sense as to what is going on in the TV series?
Then you find out that to learn what happened between these two episodes that released weekly, that you have to read 3 novels, a comic book series, watch two side-movies, watch a bonus episode, and listen to a six-hour long podcast series so you can understand Episode 8?
That is what Halo 5 required you to do in order to understand the jump in story from Halo 4.
- https://i0.wp.com/news.xbox.com/en-us/wp-content/uploads/sites/2/sdcc-halo5-transmedia-infographic-png1.png?ssl=1
Meanwhile out of Bungie’s books, the only one that could be argued as necessary was Halo: First Strike as it details how Chief, Cortana, and Johnson got back to Earth.
But even without reading the book, you don’t even need it to understand the story of Halo 2 since it is able to stand on its own without other media to act as a foundation.