343i is good in connecting the universe that Bungie, Microsoft and several book authors left behind, I'll give them that. If you care for the lore, you can find so much stuff that got further explained (Starry Night in Hunt The Truth to name an example), but people who play the campaign and don't have that much background knowledge, are having a harder time following. I bet the normal person, wouldn't know who Jul M'dama is and why Halsey is with him, something that was introduced in Halo 4's Spartan Ops and continued in a pretty bad comic series. Just like people didn't know what or who the Didact or Librarian is. Bungie did a way better job at establishing characters, even if you didn't read the books. I never had the feel that I'd have to read up something. It was always just a nice bonus to do so and I still feel like that Forerunners were better, when they were a big mystery.
Having to play a game of a franchise to know what's up is okay, but actually having to read up on certain characters in external media to understand something is not. At least in my eyes.
If you establish a trillogy or even Saga, I wish for a comprehensive and continued story. You shouldn't do things like bringing back the main villain from Halo 4 and kill him off for real this time in a stupid comic. You also shouldn't reunite Blue Team in the comic. You also shouldn't do misleading marketing that makes it seem like the story focus is about something else and then take down the trailers for whatever reason.
Just simplified my thoughts on story writing, but I think Halo under 343i has some additional underlying problems. Gameplay and level design (especially vehicular combat) is something that I'm really not satisfied with, even if some on foot sections were really great in Halo 5. I think 343i's mindset is "bigger = better" with vehicular combat and you just have to look at the Mammoth and Kraken missions to see what I mean. I actually remember someone asking "Dual Scarabs" here on NeoGAF and Stinkles replied with something like "bigger". People were excited about that and then we got the Kraken. One of the worst "vehicles" that I've ever encountered in a Halo game.