Could Infinte be taking a page from CE and have the enemy factions be revealed like how CE did it. The Banished are the main enemies for the first part of the story but then the created push them aside (as a secondary enemy) when they come in. Sort of like how the flood pushed the covenant to the side when they first appeared.
Note: This assumes the banished and created are the only enemy factions in the game
If the flood does show up at any point of the game, I would be surprised.
My bet is the Created and Humanity were fighting over the ring, then the Banished came in and really messed stuff up, which is where we come in during the Discover Hope teaser.
So when the game starts, the Banished and Created will be fighting for control of the ring, having already pushed out most of the UNSC and Master Chief. But then the first or second mission we drop back down and get to business killin’ Banished Brutes and Created Prometheans/Covenant.
I bet the Banished will be the main villain gameplay wise-- like Brutes in H3 while Elites fight alongside us-- and the Created/Prometheans might fall to the wayside like Brutes in Reach where they only show up in certain levels. Or it could be about equal, but either way I bet the Created will have more Covenant species in it then Prometheans, cause maybe lore-wise Cortana hadnt composed any people in a while and also cause everyone just hates fighting them… and they’re havent been ANY leaks regarding them, but that may be coincidence.
And I’m 50/50 on expecting the flood to be an actual enemy in gameplay and not just a tease in the last cutscene. But I have a feeling that by then end of the game theres gonna be some major change-ups in the enemy/friendly factions.