Conveying major story elements via audio logs is bad game design.
Yes I've beaten the game, there's a LOT that happened "off screen" that doesn't even get addressed. Audio logs don't count, you can't assume the player is going to take the time to hunt down every audio log and listen to them. Audio log data should be optional at best, not core story beats.
Spoiler
What happened to the Infinity? Did it get destroyed? How did the siege on the Infinity play out, and why didn't the player get to experience it? Escharum thinks Atriox is dead, why does he believe that? The revelation in the post-credits scene is that Atriox is alive, but that doesn't undo the bad storytelling of Escharum thinking he died off-camera. Cortana also "dies" off-camera, after being the sorta-villain in Halo 5 I think? There's no story arc for her following Halo 5 (redemption or otherwise), we just kind of learn at the end of the game that she did stuff and is now dead. We know nothing about the sub-Monitor and why he wants to kill you (twice!); is he siding with the Banished? Was he corrupted by the Harbinger? The Harbinger is also a non-entity; it's unclear what species she even is, and we know nothing about "The Endless" except they're apparently bad news - they never get shown in the game, and it's unclear if Master Chief even actually stopped anything by killing the Harbinger anyway.
I'm conflicted on this game. The minute-to-minute gameplay is mostly excellent and feels satisfying (although Hunters are profoundly un-fun to fight), but I found myself leaning into two weapons through almost the entire game - the plasma carbine and the battle rifle - and used essentially nothing else. Because of the verticality and un-even terrain almost all of the vehicles were useless except the Ghost and the Wasp, both of which were game-breaking and made combat encounters simultaneously trivial and monotonous because you could just spam their weapons from extreme range and not get hit as long as you were moving around a bit - I used the wasp to kill, like, half of the high-value targets this way.
A lot of the stuff like the FOBs, Marine rescues, and HVTs felt like tacked on-additions put in because it was an open-world game and the developers assumed you need that kind of stuff in open-world games. It didn't feel particularly natural or interesting, and the open-world setting didn't really enhance anything because you could approach every combat encounter the same way (like I said, BR/plasma combo or long-range vehicle sniping). All of the story missions essentially weren't open-world, and it was jarring to go from one open-world gameplay to "classic" Halo linear gameplay; none of it felt like it organically meshed like in other open-world games or like you were having a tangible effect on the world like The Saboteur, Red Faction Guerilla, Shadow of Mordor, or GTA. The environments were essentially all the same - either rocky woodlands or Forerunner structures. Gone are the different biomes of the first Halo or level variety of, well, all of the prior Halo games.
Oh yeah, there's also no way to replay story missions. Missed a skull or audio log in a story mission? Too f**kin' bad, start the game over and re-collect everything.
It seems like I'm coming down hard on the game - and I am - but while the minute-to-minute combat starts out great and the voice work from everyone is fantastic, everything else kind of starts to fall apart the more you think about it and the more the game goes on. Like, I had a real good time playing it, the grappleshot is fantastic, the soundtrack is mostly good, Master Chief's characterization and voice acting is the best it's ever been, and The Weapon is a really great character, but I'm not really in a hurry to replay the game anytime soon.
It's really clear that they cut a LOT of the game out during development, and while I'm sure delaying the game for a year definitely helped improve the game, I think an additional year could have made it fantastic.