I hope the Shadow troop transport vehicle from Halo 2 or something like it makes an appearance in Infinite. I was always disappointed that it could not be used by the player in Halo 2. Somewhere between a Warthog and an Elephant in terms of its size, speed, armor, and troop capacity, it could be a really fun element to have in social objective game types.
I feel like with the Razorback being a thing, they for sure will have others in the game. Maybe new models or old, but I think they will be fine nonetheless.