The official
Halo channel and official
Xbox channel literally call it "Halo Infinite - E3 2018 - Announcement Trailer", and use the following description of the content:
The Master Chief returns in Halo Infinite – the next chapter of the legendary franchise. Developed by 343 Industries and created with our new Slipspace Engine, Halo Infinite was revealed at the Xbox E3 2018 Briefing with a thrilling engine demo that provides a glimpse into the future of the Halo franchise, leading it into new and unexpected directions.
Some of that text may have been edited since 2018, I'm not sure but let's not pretend that this in-engine teaser of the game wasn't meant to be of the game or the engine.
I was kidding about the deer and rhinos, but...
If they used the same area back then to make what felt like different biomes, fine... they felt different in time of day and atmosphere and fauna variation, and that feeling so far is missing from Campaign previews. It gave the impression that you would go through a world with snowy mountaincaps, foggy creeks, arid deserts, craggy oceanside bluffs (where there seems to be some type of lanternfish creature? or underwater vehicle?), and... HAM radios in tents. (Not sure if that made the final game?) If that's a mistaken over-assumption, that this concept of variety was compressed geographically or in time so that it's really not a different biome but you will experiences differences in the sense of an area that makes them distinctive in time, that's a success. Right now, I'm not getting a feel yet of how areas will have distinctive senses of place, and that IMO would make it tough to connect with its open-world exploration, albeit so far its play mechanics are compelling and maybe that'll just sustain it.
I'm not even sure why you're arguing against this, even? Sure, defend & support what is there in the actual game versus what people were imagining was going to be there three years ago, okay... but there's no Halo game that looks like one single "Halo-lookin' " map. Levels look distinctive across even Halo 1, and although it's making me nervous not seeing it in Campaign previews, I'm sure there's greater variety across the full Zeta Halo than just "meadowy Halo canyon". Whether or not it's got variety that meets what I saw (or saw in my mind, I guess you're saying, in 2018 with the teaser,) that's a different thing, but there's bound to be
some diversity in the landscape. (Multiplayer already has maps made of greater variety of landscapes, so again, why are we arguing about this?) I'm not expecting some crossing of Halo and Horizon here... but I would like to see
a nice beach.