The game is cross-gen, and that makes a whole lot of sense. It's a smart move both for the franchise and the system release. Halo is not what it used to be but Infinite is gathering steam.
I personally not a Halo fan, but if it turns out to be a surprisingly strong entry, I might give it a shot on PC/xCloud.
But honestly, I wish they would have shown off Scarlet with something else. Like a truly next-gen game. It feels to me that this was a very anti-climatic release and an underutilized chance to show off the gfx benchmark of gen 9.
Vote the Mayor for Mayor!