As a suggestion for 343, once Halo 6 is done, I would definitely be in favor of an additional Halo 1, 2, 3 style game without special abilities or mobility enhancements.
I was discussing the merits of sprint in Halo with some friends. Through the discussion I ended up switching sides from being “for sprint” to being “against sprint.” The reason is simple. When every Spartan always has access to increased mobility, the maps must be designed in such a way to balance that. If you take a Halo 1, 2, or 3-style map and give everyone sprint, people just end up getting to cover too quickly, which means cover must be spread apart, and/or weapons have to do a bit more damage. Put another way, the maps where I feel like I wish I had sprint, it would be better to address it by having mancannons, teleporters, and so on.
The question arises, how to innovate in classic Halo? New awesome things can definitely be added to Halo, it’s just better if they are items on the map rather than inherent abilities that map designers have to design around. For example, Ground Pound, instead of being an ability everyone always has, could be beefed up and incorporated into a power weapon, it could be a feature of a new Gravity Hammer-style weapon. As an analogy, the Spartan Charge existed in Halo 2 in this way in the form of the Energy Sword. In addition to weapons can be new Halo 3-style deployables and power-ups.
This Youtube video says it better than I can, and highlights that innovating with items, weapons, and maps, rather than with abilities keeps the core of Classic Halo, while still being able to try new risky things. A lore reason could be given in that maybe this is an ODST or a Marine.
he explains more: