I think the implementation of a sprint mechanic within Halo 5: Guardians was quite excellent. And I hope they build off of that formula instead of reverting back to the so-called "classic" formula of no-sprint.
With that said, I do hope that Infinite provides (at least) two HCS geared Arena playlists (Team Arena & FFA for starters) that are fully tailored for that particular environment (w/ no sprint) while most remaining Arena playlists, both ranked & social, incorporate what I'd refer to as the "standard" formula that's basically a refinement on the foundation provided by Halo 5 (minus Ground Pound and Spartan Charge).
A select group of maps (~7) would need to be specifically tailored for this HCS environment. The HCS branch of 343i (with assistance from the competitive community) would have heavy input on the general experience of the environment which essentially means getting some final say on the particular elements within these modes. Elements such as: the sandbox, loadouts, spawn times, BMS, jump height, sprint, clamber, slide, boost, radar, and stabilize. In my opinion, this is where, and how, no-sprint playlists and perhaps other "no ______" aspects should fit into Infinite.
Further more, I'd love to see an expansion on the Warzone environment. It's within this particular environment that I think special Spartan Abilities such as a refined Ground Pound, a tweaked Spartan Charge, and perhaps a new take on the Jet Pack concept could be re-incorporated as a form of armor (suit) enhancement. None of these extra abilities should require a new button mechanic as they ought to piggyback off of the existing mechanics as a form of mechanical depth; plus, they ought to prevent the use of the thrust mechanism until its typical cool-down has passed.
- Ground Pound is activated by holding the melee button while in the air.
- Spartan Charge is activated by pressing the melee button while in a sprint.
- I imagine a Jet Pack-like concept could allow for a double jump to occur by having the Thruster pack provide a quick and sharp elevation boost. This would require a press of the jump button while in the air.
This manages to keep these abilities in the game, but out of the arena environment. This means that they could still exist within the campaign and they could still be used for custom games.
I also wouldn't mind seeing deloyable equipment return in some fashion too with the Up D-Pad being the means to deploy the items. Bring back the Bubble Shield, Regen Field, Power Drain, Grav Lift, Trip Mine, Radar Jammer, Solar Flare, and Deployable Cover. Plus, include an Auto Sentry & Hologram as deployable equipment too. These items could be primarily restricted to the Warzone environment, but maybe a few of them could find their way into a Big Team Battle playlist too.
By this means, Infinite would be provided with 3 levels of play: (1) a focus on competitive traditionalists who hearken for the so-called classic experience, (2) those of us who appreciate the Arena environment featuring a more robust mobility experience, and (3) an environment beyond the Arena that provides access to the full expanse of the title.
As I mentioned previously this also provides the custom game's section of Infinite a ton of variety and depth to create whatever someone may personally desire game-play wise. Plus, by not limiting Infinite to a so-called "classic" only style of play there remains plenty of interest to continue playing the MCC which has had a lot of time invested into it.