I am not saying that's the only way. Obviously Halo 4 tried *alot* of different ways to innovate. It had most of the things you mentioned: addition of new weapons, new weapon mechanics, new items, new vehicles (not this one? not sure), new vehicle mechanics, new level design ideas, new gametypes (yep, and it was hated) and gamemode (Spartan Ops).
Actually, the only advanced mechanic added to that game in base mechanics was sprint unless I'm forgetting something else. I've already stated before that I think H4 was too different. I enjoyed it, but it's kind of an objective statement that Infinity Slayer was extremely different, and it may have been the thing that 'put the nail in the coffin' for 343i (MCC launch didn't help) for a lot of the base.
Halo 5 then went all in on Arena style gameplay, with a fresh take by adding 'advanced movement'. This was still not acceptable.
So, we've seen two different approaches, a vocal group of the community hated both. One focused on all the things you mentioned, but to many it was too much at once, and change for the sake of change. The other tried to create a genuinely unique 'modern' Halo experience that I happened to have a blast playing. But people didn't want 'modern'.
So, I certainly understand. But it sounds like to me that 'acceptable innovation window' is much narrower than what you made it seem. Or, it's never acceptable if sprint is included (some have stated this clearly, and that's fine. Everyone is entitled to their opinion.)
I don't remember Halo 4 doing anything significant in terms of vehicle mechanics or level design. In fact, I'd say vehicle mechanics have been pretty stagnant perhaps since the introduction of hijacking. Not as a criticism, because I think vehicles are a difficult area to make meaningful changes in. Level design (singe player and multiplayer) has been similarly stagnant with Halo Infinite kind of making the biggest change in years in the single player realm. Multiplayer level design has been stagnant since Halo 3 came up with man cannons.
Weapons, vehicles, and modes have been the staple of change in Halo, and despite Halo 4 doing its share, i don't think it really deserves a special mention in that regard. Again, not that there's anything wrong with that. You don't need to revolutionize the sandbox or what people play to effect meaningful change.
I'm not actually sure how to categorize all the things that upset people in Halo 4. However, I can tell that the reasons people were upset was because the mechanics used in the game didn't mesh with the principles of Halo's gameplay design, and because some of the mechanics were just plain bad game design (random ordnance).
But in both Halo 4 and 5, I think there are two obvious takeaways:
- You have to be aware of the features of the gameplay design that players experience as foundational. The players may not be able to tell what these are beforehand, but they will notice when you break them.
- You can't shove too much in the player's face at once. Too much change leads to subpar execution and will come as a shock to the players. Evolution trumps revolution.