UPDATED:
On Mixer, 343 confirmed the following:
New “full-featured” Banished campaign (against the Flood) coming in the Fall of this year. This does NOT appear to be part of the Season pass. New leaders (at least 2) are part of the new campaign.
New firefight mode (different from Blitz firefight), also featuring the Flood. Build defenses, use new units, etc.
New leaders coming in June: Jerome and Arbiter. There are 2 leaders remaining for season pass content, including a 2 mini-mission.
OLD INFORMATION:
It’s confirmed that it’s a Flood expansion connected with Firefight mode. That’s about all we know now.
https://twitter.com/Danayoub/status/874333215447687170
> New HW2 Expansion - Firefight! The team worked their butts off to bring this amazing mode to you, and bring you back The Flood! #HaloWars2
Is this confirmed?? This would be the most amazing thing considering I was already content with this game this would just be a nice little bonus
Well, it’s officially from Dan Ayoub.
Also, see this tweet from Bonnie Ross: https://twitter.com/PlutonForEver/status/874323396770672640
Sounds awesome, but a little upset how they revealed this info. They decided to tweet about it first? It’s like they spoiled their own announcement. Why not release some kind of trailer first?
Announcement is coming later today at 3 p.m. P.S.T., I believe.
It looks like it’s visible at E3?
So they… Bring back the Flood in a side game that most of the Halo fanbase didn’t purchase? What, Halo 6 is going to come out, Flood is going to be everywhere, and they’ll expect everybody to just know how it happened? Seems like the worst way to bring back the franchise’s main enemy.
Unless the Flood only appear in the Firefight mode it’s and not canon. That would make sense. I mean, seeing the Flood again is cool and all, and I’m quite curious to see how this all works out. But if it really is the true return of the Flood, it sure was handled badly.
More information here from Scratch:
https://twitter.com/aka_Scratch/status/874339426024816640
> It’s pretty cool. The flood comes in waves and there are TONS of them. New defenses. Only got a few minutes with it but it was fun.
> 2533274808386392;6:
> So they… Bring back the Flood in a side game that most of the Halo fanbase didn’t purchase? What, Halo 6 is going to come out, Flood is going to be everywhere, and they’ll expect everybody to just know how it happened? Seems like the worst way to bring back the franchise’s main enemy.
>
> Unless the Flood only appear in the Firefight mode it’s and not canon. That would make sense. I mean, seeing the Flood again is cool and all, and I’m quite curious to see how this all works out. But if it really is the true return of the Flood, it sure was handled badly.
Or a genius way to.get.halo.doe.hardship to buy hw2
More from Scratch:
> I died quickly. Wasn’t ready for the rush hahah. It adds some depth as well.
What are these defenses you speak of and will this still use blitz or is it more of a horde mode with bases
Flood but not playable again??? Epic fail!!! 
THIS IS REAL??? What about Ske7ch saying no new factions? They’re gonna add the Flood (so hype) but it won’t be playable? Bruhhhhh.
I would actually be disappointed if they were working on a firefight mode instead of other aspects of the game. I don’t know anybody that plays firefight so I am not sure why they are doing this. Is there a large population that likes to play firefight? Is firefight really the best way to try and grow the userbase. Is firefight the best way to keep the game alive? I don’t think so, but if there is a large group that wants this, great!
> 2533274804660577;11:
> Flood but not playable again??? Epic fail!!!
Now bring the already a Floodfirefight and you whine around. If the community had not asked the whole time after the Flood, they would have brought the Flood perhaps not.
(sry bad english)
I think you’re epic fail.
> 2533274808386392;6:
> So they… Bring back the Flood in a side game that most of the Halo fanbase didn’t purchase? What, Halo 6 is going to come out, Flood is going to be everywhere, and they’ll expect everybody to just know how it happened? Seems like the worst way to bring back the franchise’s main enemy.
>
> Unless the Flood only appear in the Firefight mode it’s and not canon. That would make sense. I mean, seeing the Flood again is cool and all, and I’m quite curious to see how this all works out. But if it really is the true return of the Flood, it sure was handled badly.
They already said the game would tie into Halo 6’s story so is this really a surprise?
> 2533274804660577;11:
> Flood but not playable again??? Epic fail!!!
Since when were they ever besides halo 4 infection
> 2674682457271996;13:
> I would actually be disappointed if they were working on a firefight mode instead of other aspects of the game. I don’t know anybody that plays firefight so I am not sure why they are doing this. Is there a large population that likes to play firefight? Is firefight really the best way to try and grow the userbase. Is firefight the best way to keep the game alive? I don’t think so, but if there is a large group that wants this, great!
It’s probably not blitz and maybe an actual firefight mode
> 2533274805310943;17:
> > 2674682457271996;13:
> > I would actually be disappointed if they were working on a firefight mode instead of other aspects of the game. I don’t know anybody that plays firefight so I am not sure why they are doing this. Is there a large population that likes to play firefight? Is firefight really the best way to try and grow the userbase. Is firefight the best way to keep the game alive? I don’t think so, but if there is a large group that wants this, great!
>
> It’s probably not blitz and maybe an actual firefight mode
I really hope so
> 2533274805310943;17:
> > 2674682457271996;13:
> > I would actually be disappointed if they were working on a firefight mode instead of other aspects of the game. I don’t know anybody that plays firefight so I am not sure why they are doing this. Is there a large population that likes to play firefight? Is firefight really the best way to try and grow the userbase. Is firefight the best way to keep the game alive? I don’t think so, but if there is a large group that wants this, great!
>
> It’s probably not blitz and maybe an actual firefight mode
Yeah, it’s not clear. Presumably will be clear in a couple of hours.
And yes, from what I can tell, the Flood is not playable. So it’s not a faction. It’s possible, I suppose, that there’s a flood leader of some kind that runs UNSC or Banished units, but I’m literally making that up. Nothing I’ve seen so far confirms that idea.
BTW, this mode is playable on the E3 floor.
Reddit Halo says the expansion will be entitled “Awakening the Nightmare” and will be shown on the floor at 3 PM PST. So, in two hours.